Harvey’s Buttercup (Ranunculus harveyi var. harveyi*) of the Buttercup (Ranunculaceae) family has an open structure and a succulent appearance. The genus name, based on Latin words for “frog” (rana) and “little” (unculus) relates to the occurrence of many buttercups in moist habitats. The specific epithet honors Francis LeRoy Harvey, faculty member of the Arkansas Industrial University from 1876-1885, who first described the species. In the US, it occurs primarily in a broad swath from southeast Oklahoma, across Arkansas and the southeastern half of Missouri – along with widely scattered populations in several neighboring states. In Arkansas, Harvey’s buttercup is found across the Ozark Plateaus, River Valley and Ouachita Mountains – along with a few scattered counties in the southeast. Habitat includes partially to mostly sunny sites with well-drained rocky to sandy soils in upland forests and savannas.
The perennial plant has a stubby root crown supported by long, white, spreading fibrous roots and white, elongate, carrot-like, descending, smooth roots. New basal leaves appear in late fall and remain over winter. The firm, shiny, orbicular to kidney-shaped leaves have prominent cordate bases and long petioles (leaf stalks). Outer leaves tend to be prostrate (lying flat on the ground), while inner leaves tend to be ascending. Blades of young leaves are depressed at the petiole but become planar with maturity. Blade margins are broadly scalloped from the apex to the cordate base. Broadest scallop is at the leaf apex with the lateral 3-4 scallops decreasing in width toward the cordate base. Center of scallops on robust plants is marked by a tiny tip. Side-margins of scallops may overlap slightly as leaves transition to lower basal leaves with 3 lobes and/or 3 leaflets. Basal leaves are to 1¾ inches long and 1¼ inches wide with “depth” of cordate base being up to ¼ inch. Slender reddish petioles, to 2½ inches long and 1/16 inch wide, have a central groove along their upper side extending onto the blade. Petioles may be glabrous or have sparse, fine, ascending hairs alongside their central grooves. Blades of young leaves are medium green above and whitish pale-green below with lower surface becoming green with leaf maturity. Palmate veins, radiating from the petiole to blade margins, are slightly expressed above and recessed below. Basal leaves fade as flowering progresses into spring.
Photo 1: This tight cluster of 5 plants has 6½-inch-long fibrous roots and 1½-inch-long carrot-shaped, vertical roots; both smooth and white. Photo – March 30.Photo 2: These seedlings are growing in a disturbed area with compacted, rocky soil. To varying degrees, basal leaves of these half-dozen young plants are cordate. Photo – March 18.Photo 3: Overwintering basal leaves have a succulent appearance. Broadest marginal scallop is at leaf apex. Apex of each scallop marked by a tiny tip. Photo – November 12.Photo 4: Blade of center leaf, positioned to show underside, is 1¼ inches wide and ⅞ inch long with a 2¼ inch petiole. Central groove along petiole extends onto the blade. Veins are palmate. Photo – March 14.Photo 5: Basal leaves transition into lower stem leaves which may have 3 lobes (see 2 arrows) or 3 leaflets. Photo – March 18.
Stems (directly from root crown), along with primary branches (from axillary leaf buds on stem), are topped with flower buds when they emerge in mid-winter. The erect to spreading stems (one to several) grow to a final height of 6 inches to 1½ feet. Primary branches, set at 45⁰ from stems and spreading, also bear leaves which may subtend secondary branches. The longest primary branches, to 9 inches on robust plants, are lowest on the stem and often reach the same height as the central stems. The lower ⅓ to ¼ of stems and branches tend to be leafless and distal leaves are small to minute. This makes the plants look open and airy. The terete, pale-green, succulent-appearing stems and branches are hollow. They appear to be glabrous, but have sparse, relatively long, fine, ascending hairs, especially in their lower portion. The herbaceous stems and branches wither away after the growing season.
Photo 6: Plants may have a single stem. This plant (mixed with an onion) has a few scalloped basal leaves. Photo – March 31.Photo 7: Stems at various stages of growth are shown. Outer basal leaves tend to be prostrate (lying flat on the ground) while inner leaves tend to be ascending. Photo – March 2.Photo 8: The grooved petioles of basal leaves tend to be reddish while bases of the terete stems tend to be pale green. Same plants shown in Photo 1. Photo – March 14.Photo 9: Petioles may have sparse fine ascending hairs alongside the central groove. Petiole on left positioned with grooved, upper side shown and petiole of right positioned to show a side (groove to right). Photo – March 14.Photo 10: These 9½-inch-tall plants have stems with branches at 45⁰ with several additional stems still developing. Same plants shown in Photos 1 and 8. Photo – March 8.
Lowermost stem leaves of more robust plants may have 3 leaflets on petiolules (trifoliate compound) or may have 3 sessile lobes. Leaflets of trifoliate leaves tend to be broadly wedge shaped (cuneate) with straight side margins and crenulated apexes. Lobes of 3-lobed leaves tend to be narrowly cuneate with truncated apexes. At mid-stem and on branches, leaves have elongate-oblong sessile lobes changing, distally, from 3-lobed to 2-lobed and then a simple leaf with a single elongate-oblong blade. More distal leaves become increasingly small to tiny and lanceolate with the final leaf subtending the pedicel (stalk of flower). A few fine hairs may be scattered on the upper surface of leaf blades. Elongate-oblong leaflets and lobes are pinnate with secondary veins extend toward leaf apex. Less robust and smaller plants may lack both trifoliate and 3-lobed leaves.
Photo 11: Display showing a basal leaf (far right; petiole is 2¾ inches long) and stem/branch leaves of various complexity and shapes. Stems are hollow – see stem at lower center. Photo – May 1.Photo 12: Front leaf has 3 elongate-oblong lobes with sparse fine hairs on upper surface. Leaves become increasingly small to tiny toward flowers. Photo – March 14.Photo 13: This plant (6 inches tall) displays erect to spreading stems and spreading branches at 45⁰. Arrow indicates a single trifoliate leaf. Photo – March 17.
Spherical, knobby flower buds are protected by 5 thin, triangular, tightly clasping, green sepals (calyx). Flowering begins with the most distal buds as branching (and bud formation) continues. Each flower remains “open” for about 3 days with the flowering period extending from late February into April. Flowers have 5-7 petals in a single layer which may be well-spaced (5 petals) to crowded (8 petals). A typical flower has 5 sepals positioned between 5 petals, but number of sepals and size also varies. Sepals are glabrous or may have sparse long, fine hairs on their exterior. At anthesis, the now-yellowish-green and boat-shaped (naviculate) sepals are mostly hidden by petals. A tight, multi-layered ring of stamens (filaments + anthers) surrounds a spherical receptacle. Receptacle is densely covered with bright yellowish-green, exposed pistils (ovary + style + stigma). Planar, oblong petals are twice as long as sepals; shiny, smooth yellow above and a dull yellow below. Stamens (androecium), attached on a short floral axis between receptacle and petals, have thin filaments and relatively large 2-lobed yellow anthers. Pistils (gynoecium) have relatively large, flattened ovaries, tipped with a very short, straight to hooked style and a microscopic stigma. Flowers attach to short (⅛ inch) to long (1⅜ inch) glabrous, terete pedicels which are the same pale-green as branches and stems. Flowers and pedicels are glabrous.
Photo 14: Green sepals protect knobby flower buds. As petals push through the calyx, sepals shift below the corolla. Each flower is subtended by a small to tiny oblong to lanceolate leaf. Photo – March 2.Photo 15: The sessile, 3-lobed leaf at lower right has wedge-shaped lobes with truncated to crenate apexes and pinnate venation. Lengths of pedicels are variable. Photo – March 6.Photo 16: Stamens are in a tight, multi-layered ring surrounding the receptacle. Receptacle is densely covered with bright yellowish-green, exposed pistils. Photo – March 3.Photo 17: Number of petals and size and shape of sepals is variable. Flower on right is ½ inch wide and one on left is ⅝ inch wide. Photo – March 23.
Fertilized ovaries enlarge to form flattened, ovoid, 1/16 inch long, glabrous achenes with a short persistent style/stigma (apex). Apex may be straight to slightly hooked. Sepals, petals and stamens drop-off to leave a globose head (less than ¼ inch long) of developing achenes. After achenes drop-off, a slightly elongated, pale-green, bumpy, glabrous to sparsely hairy receptacle remains.
Photo 18: Achenes are flattened, ovoid and glabrous with a tiny, short-curved apical hook. Squares = ¼ inch. Photo – May 1.
As a volunteer-plant in a garden or natural setting, Harvey’s Buttercup can add a spot of green overwinter and shiny yellow flowers in spring. This buttercup may be the first to bloom. Flower size is intermediate between the “small-flowered buttercups” (see next paragraph) and large-flowered buttercups such as, Early Buttercup (R. fascicularis) and Hispid Buttercup (R. hispidus var. hispidus). Pollen and nectar attract various bees and flies. Seed eaten by game birds and small mammals. Not noted to spread aggressively by seed.
Two of the other 17 species of buttercups in Arkansas have a similar appearance to Harvey’s buttercup in terms of basal leaf shape, overall plant structure, and yellow flowers: Kidney Leaf or Small Flowered Buttercup (R. abortivus) and Rock or Small Flowered Buttercup (R. micranthus). R. abortivus can be distinguished by its smaller flowers, glabrous stems and pubescent receptacle. R. micranthus can be distinguished by its smaller flowers, truncate to cuneate basal leaves, villous stems and glabrous receptacle.
Article and photographs by ANPS member Sid Vogelpohl
Yellow Honeysuckle (Lonicera flava) of the Honeysuckle (Caprifoliaceae) family is a twining vine with terminal clusters of yellow tubular flowers favored by swallowtail butterflies. The genus name honors Adam Lonicer* a German physician, botanist, and herbalist of the 16th Century. The specific epithet is Latin for “yellow”. In the U.S., principal areas of occurrence are 1) from south and eastern Oklahoma, thence eastward across Arkansas and into the southern half of Missouri and 2) in a disjunct area from northeastern Alabama into the southern Appalachians of North and South Carolina. In Arkansas, it occurs across the Interior Highlands (Ozark Plateaus, Arkansas Valley, and Ouachita Mountains). Preferred habitats have loamy to rocky, dry to mesic, acidic to basic soils on bluffs and ridgetops and in open woodlands and along woodland margins with full to partial sunlight.
Vines have conical, glabrous, axillary buds protected by imbricated scales that loosen as new growth emerges in mid-winter. New vegetative (i.e. non-flowering) stems emerge from axillary buds of previous year’s leaves or from adventitious buds (formed within the cambium layer) along an upper stem. They may grow 6+ feet long in their first year. On older plants, new vegetative stems may also emerge from adventitious buds at the top of the rootstock which may grow to 10+ feet long in their first year. The weakly twinning, newly emergent stems are initially strongly ascending, but, with lengthening, orientation becomes horizontal before the weighty distal portion becomes down-trending. To a limited extend, stems may also tightly spiral about a support. New stems bear decussate pairs (rotated 90⁰) of opposite lateral leaves, subtending an axillary bud, and a final leaf pair subtending a single terminal bud. In the new growth-year, due to the down-trending stems, ends of year-old stems die with new axillary stems (and branches – see below) emerging from buds along the elevated portions of the stems. Plants, with stems forming a loose, open to dense viny mass within supporting vegetation, may reach heights of 20+ feet and widths of 10+ feet wide. When a pair of equal-vigor stems (or branches) emerge from opposite axillary buds, in subsequent growth-years, one stem dominates, and the weaker stem dies. The initially pale green, terete, hollow, glabrous stems become woody and tan during their first growth-year with their thin bark. Bark, after several years, exfoliates into strips – most noticeable at plant-base.
Photo 1: These new strongly ascending stems, emerging from adventitious buds on the rootstock, have opposite decussate leaf pairs. Bark of the old, woody stems is exfoliated. Photo – April 8.Photo 2: New axillary stems of this plant (upper portion of photo) seek support to gain height. Several twinning stems can be seen (lower portion of photo). On lower-left, branches of this hickory tree have been cut-off by a Twig Girdler (Oncideres cingulata). Photo – April 9.Photo 3: Horizontal to down-trending, year-old woody stems are fixed in position. New growth (mostly “mixed” branches – see below) is from axillary buds along the elevated portion of year-old stems. Photo – April 10.
Axillary buds also produce short, glabrous, non-twinning branches. Branches may be vegetative (leaves only) or bear leaves and flowers (“mixed” herein) – both with opposite leaf pairs that are smaller and closer together at branch-base (see Photo 9). Vegetative branches have 2 to 6 pairs of opposite, lateral leaves and a terminal leaf pair. Mixed branches have 2 to 6 leaf pairs, of which the terminal leaf is formed by the fusion of a leaf pair around a terminal “extension” of the branch (aka peduncle – stalk of an inflorescence). Such a fused leaf is referred to as being connate-perfoliate. As is true for stems (see above), vegetative branches have a final pair of elliptic leaves subtending a single terminal bud. Lateral branch leaves subtend axillary buds which may produce weak branches in the next growth-year, often only from the uppermost buds. Subsequent growth of branches, after the first growth-year, is limited and branches die-out within a year or two.
Photo 4: These new-growth branches have emerged from opposite axillary buds on a year-old, smooth, woody stem. The branch-node has a ridge between the new branches. Photo – March 4Photo 5: Vegetative branches (center of photo) have a final pair of elliptic leaves subtending a single terminal bud. Final leaf of mixed branches (see budded-cluster on right) is a connate-perfoliate fusion of two opposite leaves. Photo – April 10.Photo 6: This mixed branch grew from an axillary bud at the base of the previous year’s infructescence (see arrow). Tiger Swallowtails (Papilio glaucus) (male shown) favor the nectar. A Twig Girdler pupa has ventilated the hickory branch at upper left. Photo – April 11. Photo by Jeanette Vogelpohl.
Early leaves of vegetative and mixed branches tend to have blue-gray to reddish shading. Mature early leaves and more distal leaves have a medium-green upper surface and gray-green lower surface. The sessile to short-petiolate leaves, to 3½ inches long and to 2½ inches wide, are elliptic to ovate with entire (smooth) margins. Bases of blades vary from broadly rounded to blunt to wedge-shaped and apexes are similarly shaped. Blades of mature leaves are undulated, in irregular fashion, from midribs toward side-margins. Pubescence of leaves is limited to veins of the lower surface, especially along midrib and secondary veins. While the light-colored upper veins are expressed and channeled (slightly sunken beside their elevated center-line), lower veins (same color as blade) are expressed with a depressed center-line. The off-set pinnate secondary veins divide into tertiary veins midway to leaf margins.
Photo 7: These short-petiolate, ovate leaves are on glabrous stems. In photo, upper surface shown higher than lower surface. These leaves have rounded apexes and rounded to wedge-shaped bases. Photo – October 30.Photo 8: Midrib and secondary veins of lower surface are pubescent; straight hairs on veins and woolly hairs of midrib. Lower veins are expressed with a depressed center line. Photo – October 30.
The oval to elongate-ovate connate-perfoliate leaves are to about 6 inches long and 2 inches wide. The smooth margin may be indented where bases of the two leaves fuse and the leaf may have a slight notch or tip at the apexes. Upper surface of leaves may be slightly glaucous (blue-gray) toward midvein and petiole/branch. Other characteristics of perfoliate leaves are the same as noted for elliptic leaves.
Photo 9: Upper and lower sides of sessile elliptic leaf-pairs and a terminal connate-perfoliate leaf are shown. Lowermost leaf-pairs (on right) are closer together. Leaf size increases distally. Upper veins have a lighter color than the blade. Photo – April 5.
Buds have a slender corolla tube, set on a free-standing ovary, that expands into an inflated upper portion sealed by overlapping corolla lips. Flowers, blooming in early spring over several weeks, are in a terminal cluster of 1 or 2 whorls with up to 6 sessile flowers per whorl arranged radially around the terminal extension. A short segment of a branch’s terminal extension separates the lower whorl from the connate-perfoliate leaf and the upper whorl (if present). The terminal extension ends with a flat-top surrounded by the sessile flowers. Flowers in a whorl bloom as a group with the lower whorl (if 2 whorls) reaching anthesis first. Flowering is most profuse in sunny sites and on the sunniest portions of a plant. Except for tiny bracts at the base of each whorl, the inflorescence is without leaves or bracts.
Photo 10: These buds are in 2 whorls separated by a short terminal extension of the branch. Leaf pairs and the terminal leaf are rotated 90⁰ from each other. Year-old stem on left has shredding bark. Photo – March 20.Photo 11: The connate-perfoliate leaf and the two whorls are separated from each other by a short segment of the branch’s terminal extension. Budded flowers have a slender tube and an enlarged upper portion sealed with overlapping lips. Photo – April 5.
The bright yellow tubular flowers (to 1¼ inches long) have 2 lips, a broadly open throat and a slender corolla tube set on a smooth pale-green ovary. The relatively narrow lower lip, gently recurved downward, has a narrow lower portion gradually widening distally but still significantly narrower than the upper lip. Upper lip, gently recurved upward, is broad with 3 shallow lobes along a wide apex. Flowers are glabrous except for straight hairs inside the tube. The sessile flowers have 5 prominent stamens (filament + anther) and a pistil (ovary + style + stigma), both yellow, that extend well beyond the lips. Projecting stamens, adnate within the lower portion of the tube and recurving slightly in consonance with the upper lip, have slender filaments with elongate anthers attached see-saw fashion. Pistil, more slender and straighter than the filaments, projects away from the anthers, with the broad-flattened stigma extending further than the anthers. The glabrous, green ovary is free (fully exposed). The prominent anthers dehisce along longitudinal lines to release yellow pollen. Flowers become orange as they wilt and drop off cleanly.
Photo 12: Whorls have up to 6 flowers arranged radially around the terminal extension of the branch. Upper leaf surface may be slightly glaucous (blue-gray). Photo – April 16.Photo 13: Stamens project well beyond the corolla and recurve slightly in consonance with the upper lip. Pistils project away from anthers. Pollen is yellow. Female Tiger Swallowtail shown. Photo – April 10.Photo 14: Elongate anthers are attached see-saw fashion to slender filaments. Lines along front-side of anthers mark where anthers will dehisce to release pollen. The broad-flattened stigma is sticky to collect pollen. Photo – April 5.Photo 15: Stamens are adnate within lower portion of corolla tube. As shown, interior of tube is pubescent. This pistil is 1¼ inch long. Photo – April 5.
Ovaries of fertilized flowers expand into pale-green elongate-spherical fruits (berries). Berries are glabrous with their apexes marked by a small, rimmed flower-scar. Mature berries, bright red with orange flesh, may remain red into winter before becoming dark and shriveled on the vine, if they are not eaten by wildlife. The 1-5 brown, lightly textured, thickened, ovate seeds are about ¼ inch long and somewhat narrower in width.
Photo 16: This 2-inch long connate-perfoliate leaf is notched at its apexes and side margins. The top of the branches’ “terminal extension” (peduncle) can be seen at the center of the cluster of berries. Berries have a rimmed flower-scar at their apexes. Photo – June 1.Photo 17: Stems loosely twine and sprawl within branches of this supporting tree. Berries can be seen in lower portion of photo. Photo – November 18Photo 18: With favorable moisture, fall foliage becomes yellow and berries remain red into late fall. Largest berry shown is ⅜ inch long and wide. Photo – December 5.Photo 19: Ovate seeds become brown. Dried berries are shown at upper left and lower right. Squares = ¼ inch. Photo – October 1.
In a sunny garden or natural setting that has small deciduous trees and well-drained soil, Yellow Honeysuckle is an excellent vine for its showiness and value to wildlife. It can trail along ground and may serve as a coarse groundcover. New plants may need assistance to become established on/within a supporting tree or structure. For best flower and fruit display, trimming should be minimized. It is especially showy in bloom but has interesting characteristics throughout the year. Yellow Honeysuckle provides food and shelter for wildlife. It is a favorite vine of hummingbirds and swallowtail butterflies and the loose, viny mass of mature vines provide excellent cover for nesting birds. Not aggressive by vine or seed. Fall foliage may become a strong yellow.
Three additional vining honeysuckles in the Lonicera genus occur in Arkansas; two are native and one is invasive. The two native species have connate-perfoliate terminal leaves, terminal tubular flowers and red fruit, similar to Yellow Honeysuckle. Native Grape Honeysuckle (L. reticulata) has shorter pale-yellow flowers in 5+ whorls so that the infructescence is grape-like. Native Trumpet Honeysuckle (L. sempervirens), has 5-lobed trumpet-shaped flowers that are red outside and yellow inside (rarely, all yellow). Non-native and highly invasive Japanese Honeysuckle (L. japonica) has tubular white to yellow axillary flowers, purple-black fruits and lacks connate-perfoliate leaves. Three non-native invasive shrubs of the Lonicera genus also occur in Arkansas: Fragrant Honeysuckle (L. fragrantissima), Amur Honeysuckle (L. maackii) and Morrow’s Honeysuckle (L. morrowii).
*Also known as Adam Lonitzer and Adamus Lonicerus (1528-1586). His first important illustrated work on herbs, the Kräuterbuch, was published in 1557.
Article and photographs by ANPS member Sid Vogelpohl
Hooked Buttercup (Ranunculus recurvatus var. recurvatus*) of the Buttercup (Ranunculaceae) family, one of 17 yellow-flowered (sometimes white) buttercups in Arkansas, has achenes (fruits) with prominently hooked beaks. The genus name is based on Latin words “rana” meaning frog and “unculus” meaning little and relates to the occurrence of many buttercups in moist habitats. The specific epithet is a reference to the hooked beaks on the fruits’ achenes and a source of its common name. It occurs throughout much of the eastern U.S., east of line from eastern Texas to Minnesota, excluding most of Florida and southern Georgia. In Arkansas is occurs statewide. Preferred habitats consist of shaded to lightly sunny sites with wet to mesic, fertile soils in elevated and low-lying woodlands and shady seeps. It is also known as Small-Flower Buttercup and Hooked Crowfoot.
This herbaceous perennial develops a thickened, white, central rootstock supported by white, spreading, ropy roots. It has basal leaves on long stalks (petioles) and well-spaced, mostly petiolate leaves on flowering stems (cauline leaves) that may grow to 24 inches tall. Basal leaves of young plants are round with slightly notched margins. Leaves of flowering plants, both basal and lower-cauline, are palmate (hand-shaped). Exterior margins of palmate leaves have prominent teeth which may be dentate (pointed) to crenulated (rounded). In broad-outline, palmate leaves (¾ – 3 inches long and 1- 4½ inches wide) have deep incisions (not cutting to the petiole) so that blades are 3 lobed with a shallowly to deeply cordate (heart-shaped) base. Less complex palmate leaves have a broad terminal lobe and an opposite pair of broad lateral lobes. Lateral lobes of more complex palmate basal leaves have an additional less-deep incision, so that leaves may appear to have 5 lobes. Margins of incisions are straight and lack teeth. Terminal lobes, with both side-margins formed by incisions, are cuneate (wedge-shaped) while lateral lobes, with only an interior-margin formed by an incision, are also rather cuneate but with the exterior-margin bearing teeth. Basal and lower cauline leaves have slender, terete petioles with shallow grooves along the adaxial side. Purplish petiole bases of basal leaves have short sheathes. Marginal teeth and crenulations are mucronate (terminating with a tiny, abrupt tip). Upper leaf surface is medium to dark green while lower leaf surface is lighter green. Minute fine pubescence across adaxial (upper) leaf surface is appressed. Fine pubescence of abaxial (lower) surface (primarily along veins and nearer the petiole) and margins (ciliate pubescence) is slightly longer and spreading (erect). Pubescence coarsens and decreases with age.
Photo 1: A young plant and a mature plant are shown. Plants develop a thickened central rootstock supported by long ropy roots. As arranged, mature plant is 12½ inches long. Photo – September 9.Photo 2: Central rootstock of mature plant shown in previous photo. Brown-rimmed longitudinal markings are growth rings of the rootstock while elevated areas with spiky remnants persist from bases of previous years’ leaves and stems.Photo 3: Backside of rootstock shown in previous photo. Additional remnants of previous years’ leaf and stem growth can be seen. These leaf bases are pubescent and purplish. Basal sheathes can be seen on leaf on left.Photo 4: Leaves of this young plant (upper leaf = ½ inches across) have margins that are crenulated along with slight incisions. Adaxial pubescence can be seen on leaf at right. Photo – May 30.Photo 5: Deep incisions create a terminal lobe and a pair of lateral lobes. Less-deep incisions cut into the lateral lobes so that a leaf appears to have 5 lobes. Blade is 4 inches long and 5 inches wide. Violet Wood Sorrel at left. Photo – April 12.Photo 6: The reddish-purple leaves survived overwinter while the green leaves developed in mid-winter into spring – younger leaves with 3 prominent lobes. Photo – March 20.
Cauline leaves vary greatly in shape and size. Large 3-lobed lower-cauline leaves, similar to 3-lobed basal leaves, become less complex up-stem with lobes decreasing in number and becoming narrower. The more distal leaves reduce in size and complexity to the point that uppermost leaves become oblong to lanceolate with smooth margins. Petioles of lower-cauline leaves are about same length as basal leaves, with lengths decreasing distally to the point that more-distal, more simple leaves are sessile. Venation pattern, recessed above and expressed below, varies with leaf and lobe shape in that broader lobes have palmate veins while narrow lobes and elongate leaves have veins that appear almost parallel.
Photo 7: Incisions, not cutting to the petiole, may be narrow (Photo 5) or well-spread (as shown). Photo – March 29.Photo 8: Small leaf at lower left is from first-year plant. Large leaf at right is a basal leaf of mature plant. Other leaves are cauline, decreasing in size and complexity up-stem. Venation, recessed above and expressed below, may be palmate or almost parallel, depending on shape of leaf/lobe Photo – May 29.Photo 9: Abaxial side on left; adaxial side on right. Teeth terminate with a tiny, abrupt tip. Spreading pubescence of petioles and abaxial side of leaf (left) as compared to scattered, appressed pubescence of adaxial side (right).
Stems become apparent when first flowers open just above unfurling cauline leaves. Mature plants have one to a half-dozen stems that grow separately from the central rootstock. As stems elongate, cauline leaves become widely spaced with the lowermost leaf being well above the soil. Overall, leaves are usually alternate, but leaves can be in pairs. Upper leaves subtend a single axillary branch. Branches, with their own leaves and axillary buds, may further divide into branches of decreasing size. Branches terminate with a single flower on a peduncle (flower stalk) to 1+ inch long. Stems and branches are moderately to densely covered with spreading, straight white hairs, decreasing distally to the short, antrorse (bent forward) pubescence on the peduncles. Stems remain erect, but with several stems with dividing branches, plants may spread wide from plant-center and develop a congested appearance. Stems and branches are the same medium to dark green of upper leaf surfaces. Stems do not root at nodes.
Photo 10: Overwintering and early basal leaves fade with growth of stems. Lower portions of stems are leafless. Cauline leaves often occur in pairs of which each subtends a branch (see arrows). Photo – May 30.Photo 11: This leafy, robust plant may have a half-dozen stems. When leaf lobes are narrower, as are those of this plant, veins appear parallel. Larger yellow flowered plant to upper left is Celandine Poppy. Photo – April 21.
Flowering occurs for about 30 days, primarily during April. Flower buds are round to elongate in side-profile and, in top-view cross-section, are round with 5 bulges formed by sepals. Overall structure of the inflorescence is a panicle with cymose branches terminating with single flowers. The perfect flowers (with stamens and pistils) reach anthesis sequentially from early to later branches. The small flowers, ⅓ inch across, have 5 pale-yellow petals, a ring of 30± stamens (filaments + anthers) and 5 pale-green sepals (¼-inch long). The lanceolate to oblong-oblanceolate petals, <¼ inch long and 1/10 inch wide, are half the length and significantly narrower than sepals. The widely spaced petals are ascending to spreading in a star-pattern with the sepals in-between. Stamens, in a single or double series, surround the receptacle bearing a dense cluster of bright-green pistils (ovary + style + stigma). The flattened, ovoid, asymmetrical pistils are arranged radially with a hooked style, tipped with a pinpoint stigma, directed away from flower center and downward. Stamens, with 2-lobed pale-yellow anthers facing upward and outward, recurve toward flower-center. Anthers, after releasing pale-yellow pollen, thin as the stamens elongate to become tongue-like before dropping off.
Sepals, stubby when flowers are in bud, continue to grow as flowers open. At anthesis, the elongate-triangular sepals are sharply reflexed to drooping from near their bases. Interior side of sepals is whitish and smooth while exterior is pale green with especially long, weak, fine, straight hairs. Sepals, along with petals and stamens, quickly drop off the receptacle as anthesis progresses. Development of the infructescence proceeds quickly.
Photo 12: Flower buds (see arrows), when viewed from above, have 5 marginal bulges which represent the sepals. Petals form a star-shape. After pollen release, stamens with 2-lobed anthers (lower flower), thin and elongate (upper flower). Photo – April 14.Photo 13: Leaves reduce in size and complexity distally with uppermost leaves being oblong to lanceolate with entire margins. Sepals become strongly reflexed from near their bases. Photo – April 11.Photo 14: Stamens, petals and sepals quickly drop off. The large 3-lobed leaf will, with stem growth, be located below mid-stem. Photo – April 21.
With fertilization and ovary growth, the pistil-bearing receptacles become a fruit-head about ¼ inch long and ⅛ inch wide. The globose heads consist of a dense cluster of ovoid achenes with a slightly thickened center, smooth margins and minutely roughened sides. Achenes have a distinctive beak that projects from along their upper margin downward in alignment with the achene’s principal plane. The flattened beaks taper abruptly to a hooked sharp, non-piercing point. The loosely attached achenes fall off to reveal an elongate receptacle with numerous long, spreading white hairs. Seeds, brown when dry, may be dispersed by passing animals and surface runoff following heavy rain.
Photo 15: Robust plants, as shown, may have dense branching and bear hundreds of small flowers. Photo – April 30.Photo 16: Erect to spreading branches continue to grow until the inflorescence has faded. Current-year’s seedlings are at lower left. Photo – May 21.Photo 17: Fruit-heads on short to long peduncles, beginning at the final branch nodes (see arrows). Beaks of fruits project outward and downward. Pubescence of peduncle is antrorse (bent upward). Photo – May 21.Photo 18: With 40+ achenes removed from the receptacle, its fine pubescence is seen. The flattened, ovoid achenes have a slightly thickened center. Squares = ¼ inch. Photo – June 1.
Hooked Buttercup is most showy in spring when plants are most leafy and bearing small flowers. The pale yellow petals and stamens, along with the larger pale-green sepals, drop off cleanly as the shinny-green pistils enlarge into seeds (achenes) with the same shape. By late spring, with maturing seed, plants are nearly leafless and assume a scraggly appearance. Flowers provide nectar and pollen for small bees and seed for game-birds and small mammals. Seed readily germinate, but the species has not been noted to be aggressive, in part, because bare soil is needed for seedlings to survive. Hooked Buttercup is also known as Blisterwort because of an oil (glycoside ranunculin) in its foliage and stems can cause blistering in the mouth area and abdominal pain when ingested by herbivores and humans.
Sixteen other yellow-flowered (sometimes white) buttercups occur in Arkansas of which 2 also have small flowers: Kidney-Leaf Buttercup (R. abortivus) and Rock Buttercup (R. micranthus). Both are also called Small-Flower Buttercup and have distinctive lower oval to ovate to reniform leaves. Hispid Buttercup (R. hispidus var. hispidus) has similar 3-lobed leaves, but the terminal lobe is typically stalked, flowers are significantly larger, and beaks of achenes are nearly straight. Another buttercup addressed in this series of articles is Early Buttercup (R. fascicularis) which has leaves and flowers that are significantly different than Hooked Buttercup and has tuberous roots.
*A second variety of the species (Ranunculus recurvatus var. tropicus) occurs in the Caribbean Islands.
Article and photographs by ANPS member Sid Vogelpohl
Blunt Lobed Woodsia (Woodsia obtusa subsp. obutsa*) of the Lady Fern (Woodsiaceae) family is a small to medium size, evergreen fern with thin leaves (fronds). The genus name recognizes Joseph Woods (1776-1864), an English Quaker architect who authored several books on plants of Europe and the British Isles. The specific epithet is Latin for “blunt”, a reference to the shape of leaflets (pinnae). In the U.S., it occurs in a broad swath from central Texas to southern Maine, extending as far north as the Great Lakes and as far south as the Florida panhandle. In Arkansas, Blunt Lobed Woodsia occurs statewide. It grows in shaded to partially shaded woodlands and thickets with well-drained mesic loam to rocky soils over limestone or sandstone, often in shaded embankments. It is also known as Blunt Lobed Cliff Fern. Ferns have a two-phase life cycle**.
Photo 1: Fronds of young plants (on left and above), shown with pine needles, are simpler than those of mature plants. Plant below fern is a species of Liverwort. Photo – June 14.Photo 2: Crevices between stacked rocks provide a favorable habitat for this fern. Significantly larger plants grow in deeper soils. Photo – October 5.
Plants, occurring singly or in small to large clumps, have elongate rhizomes with a narrowed, rounded base (point-of-origin) and a terminal bud from which fronds grow. Terminal buds may divide (ramify) into a pair of terminal buds which elongate into separate limbs of the rhizome. Fronds, growing from all “sides” of the terete (round in cross-section) rhizomes, twist sharply upward around the terminal bud to exit soil vertically as a compact cluster of fronds. The shallow, slow-growing rhizomes, ⅜ to ¼ inch diameter, are supported by a dense mat of spreading fibrous roots with long, unbranched thread-like central rootlets that bear closely spaced short lateral rootlets. Spiky, rather fragile, stalks (stipes) of dead fronds persist for a year or two. New fronds, appearing as coiled fiddleheads, are either fertile (bearing spores) or sterile (lacking spores) fronds.
Photo 3: This single, evergreen plant has a dense mat of fibrous rootlets; as shown, spread-out 10 inches. The straw-like stems are dead stipes of fertile fronds from the current growth-year. Photo – December 20.Photo 4: Same plant as in previous photo, tilted to show underside of the rhizome. Point-of-origin indicated by an arrow. The rhizome has three limbs of which the limb on right, from the point-of-origin to the terminal bud, is 2½ inches. Photo – December 20.Photo 5: Supporting root mass consist of very long, thread-like central rootlets (dark) with short lateral rootlets (orange). Central rootlets extend from right to left. Photo – December 20.Photo 6: View of the terminal end of a ½ inch wide rhizome. Terminal bud is encircled by fronds emerging from all sides of the rhizome and twisting upward to emerge from the soil. Photo – December 2.
Size of plants varies considerably depending on soil moisture, soil depth, and sunlight. Early in the growth-year, sterile and fertile fronds have about the same appearance. By mid-spring, with development of spore-bearing structures (sporangia), fertile fronds become erect and spacing between pinnae pairs widens. While sterile fronds are produced throughout the year, fertile fronds appear in early spring and die after spore release in midsummer. The brittle, persistent stipes of dead fertile fronds are not articulated so that remnants of stipes are of various lengths.
Fronds have prominent scales and minute glandular hairs. The whitish to light brown translucent scales, scattered along the stipe and rachis (stalk bearing pinna), and costa (stalk bearing pinnae), become fewer and smaller toward frond apex. With frond maturity, scales drop-off. Without magnification, glandular hairs are not noticeable. The sparse to dense glandular hairs, with or without bulbous tips, may cover stipe, costa, and pinna.
Photo 7: These fiddleheads, uncoiling into erect fronds with widely spaced pinnae, are fertile fronds. Translucent scales can be seen scattered along the rachis. Photo – March 25.Photo 8: With enlargement of previous photo, dense glandular hairs become more obvious. Photo – March 25.
Fronds, 6-15+ inches long and to 3+ inches wide, are cut into 6-16 pairs of closely spaced (sterile fronds) to widely spaced (fertile fronds) pairs of pinnae. Pinnae, in turn, are cut into 4-14 opposite to alternate pairs of sub-leaflets (pinnules); a twice-cut fern. In outline, shorter sterile fronds are broad-elliptic, while longer fertile fronds are lance-elliptic. Fronds, widest along their mid-section, are pale to medium green on upper and lower surfaces. A central abaxial groove along stipes extends onto the rachises, costae and becomes the mid-vein of pinnules. Blade tissue is thin. Pinnate veins are obscure on both the upper and lower surfaces. Lowermost pair of pinnae on fertile fronds is noticeably shorter.
Photo 9: New fronds, with scales, are emerging from a terminal bud at lower left and a second bud at lower-center. Both buds are probably on separate limbs of the same plant. Veins are obscure. Photo – March 22.Photo 10: Early fertile and sterile fronds have about the same appearance. Fern at lower left is Ebony Spleenwort. Photo – April 17.Photo 11: Fertile fronds (shown) are typically more erect and have wider-spaced elongate pinnae. These are 15 inches tall. Photo May 31.
Paired pinnae, elliptic to ovate-elliptic in outline, are typically opposite to near-opposite, Pinnae pairs may become alternate above mid-frond and, approaching the frond apex, shortening pinnules become closely spaced to merging. Pinnae, with very short stalks (petiolules), are set at a right-angle to the rachis, with the entire pinnae gently angled toward the apices. Pinnae have narrowly to broadly acute (occasionally attenuate) apices. Pinnae of fertile leaflets are often narrow and pointed.
Pinnules may be rounded (typically for infertile fronds) or oblong (typically for fertile fronds). Those that are lower on pinnae, may be cut to the costae into “independent” pinnules or, those that are more distal, not cut to the costae so that they are lobe-like. The sessile pinnules are attached at about 45⁰ to the costae and trend toward tips of pinnae. Margins of pinnules typically have closely spaced, irregular, dentate to crenate teeth to shallow lobes. Pinnules decrease in size and merge distally to form an acute to obtuse apex. While sterile fronds typically have rounded pinnules, those of fertile fronds are typically elongate but may also be rounded. Margins of pinnules may be turned under (revolute).
Photo 12: Typically, pinnae of the sterile fronds (upper left) are more rounded than those of fertile fronds (lower right). An abaxial groove along the rachis and costae continues as midrib of pinnae. This fertile frond has revolute margins. Photo December 2.Photo 13: Upper sides of two fertile fronds shown. Lowermost pinnae are noticeably shorter and pinnules are rounded. Pinnae pairs are opposite and alternate. Left frond is 8 inches long and 3⅜ inches wide. Photo – April 30.
In mid-spring, circular, pale-green sori (sporangia-bearing structures) appear on the underside of fertile fronds. Sori (1/32-inch wide), singly or in groups of 2-3 per pinnule are in a line from pinnule-base to pinnule-apex. Sori are located between the pinna-midrib and side-margin. Within each sorus, 4-10 bead-like, light tan sporangia produce spores protected by a dome-like translucent indusia attached below the sorus. In late spring into early summer, the indusia splits across its top into irregular, broad-based segments which shrink away from the sporangia in star-pattern fashion. The sporangia splits on a dry day to release dust-like spores for wind dispersal. After spore release, sporangia have a frazzled appearance.
Photo 14: A pair of fertile pinnae with upper and lower sides shown. Pinnules bear one to several sori. These lobe-like pinnules merge toward the apex of the pinnae. A scale-covered costa is positioned between the pinnae. Photo – May 1.Photo 15: A closer view of the pinnae shown in previous photo. Note minute glandular pubescence extending from costae onto pinnules. Photo – May 1.Photo 16: As shown, the indusia of the sori have shrunk back to expose 4-10 sporangia per sorus. Pinnules of these fertile fronds are oblong with crenate, mostly un-cut margins. Photo May 31.Photo 17: With most spores having been released, the sporangia have a frazzled appearance. Note the dense glandular pubescence. Photo – June 27.Photo 18: Sterile fronds are evergreen after hard-freeze temperatures while fertile fronds are represented by brown stipes. One dead fertile frond (not shown) was 17½ inches long. Photo – December 19.
Blunt Lobed Woodsia may be a good choice as an accessory or in-fill plant in various garden settings that have partial to full shade with well-drained, preferably mesic, loamy to rocky soils. A good choice for fern gardens, rock gardens and natural areas. The fern may establish itself if a favorable environment is available. It is a compact, small to medium sized, evergreen fern with delicate fronds. Although it is an evergreen fern, fronds of established plants die with dry soil but new sterile fronds readily emerge with renewed moisture. Not suitable for wet soils or full sun.
Photo 19: A naturally occurring blanket of Blunt Lobed Woodsia growing in a thin-soil glade among Eastern Red Cedar (Juniperus virginiana). Photo – May 15.
Appalachian Cliff Fern (Woodsia appalachiana) is recorded from Logan and Perry Counties. Appalachian Cliff Fern, although generally similar to Blunt Lobed Woodsia, can be distinguished by having 1) frond stems that are chestnut brown to straw-colored, 2) scales on stipes only and 3) indusia that have several oblong lobes to one side. Blunt Lobed Woodsia has 1) pale green frond stems, 2) scales on stipes and rachises and 3) indusia lobes that open into a star-shaped pattern.
*A second subspecies of Blunt Lobed Woodsia occurs in Arkansas. Western Cliff Fern (Woodsia obtusa subsp. occidentalis) has smaller spores (measured in micrometers), rhizomes that are longer and thinner, and more finely divided leaflets.
**Ferns have a two-phase life cycle: the leafy sporophyte phase (two sets of chromosomes in each cell) and the microscopic gametophyte phase (one set of chromosomes in each cell). During the sporophyte phase, ferns bear leaves (fronds) of which some bear clusters of spore-producing sporangia in sori (aka fruit dots). Often, developing sori are protected by thin covers (indusia). The indusia split or shrink-back so that sporangia are exposed releasing spores into the breeze. A spore in a favorable environment, initiating the gametophyte phase, develops into a prothallus containing a structure (archegonium) which forms an egg and another structure (antheridium) which forms sperm – egg and sperm each having one set of chromosomes. Sperm moves through moist soil to join with an egg to produce a single cell zygote which grows a root into the soil (“point of origin” as used herein in regard to the rootstock) to begin the sporophyte phase.
Article and photographs by ANPS member Sid Vogelpohl
Hop Hornbeam (Ostrya virginiana) of the Birch (Betulaceae) family is a woodland to woodland-margin tree with staminate (male) and pistillate (female) catkins on the same tree (a monoecious species). The genus name is based on Latin and Greek words for “scale” in reference to prominent scale-like bracts on early catkins. The specific epithet is in reference to the species’ original description from the colony of Virginia. In the U.S., its occurrence is widespread across the eastern half of the country, extending into southeastern Canada. In Arkansas, it occurs statewide except for some low-lying areas of the Mississippi Alluvial Plain. It is adaptable to a wide range of climates and soils with preferred habitats in Arkansas trending toward wooded-deciduous environments on well-drained north slopes and lowlands; along with woodland margins, stream banks and open areas. Other common names include Eastern Hornbeam and Ironwood. The “hop” portion of the common name is a reference to the similarity of the tree’s aggregated fruits to those of Wild Hop vine (Humulus lupulus), a variety of which is an Arkansas native of conservation concern. The word “hornbeam”, originating from the European Hornbeam (Carpinus betulus), relates to hardness of its wood (may be polished to a shine like horn) and the Old English word for tree (beam) or, alternately, may refer to the use of the wood as yokes (beams) between horned oxen.
This small to medium-size deciduous tree may grow a foot per year when young but has slow growth by the time it reaches flowering stage at 20+ years. Trees, growing to 40 feet tall and 25 feet wide*, may have a single trunk or several near-ground trunks of varying size. Long, lower branches tend to be horizontal to slightly drooping while upper limbs are ascending. Lower branches drop-off cleanly as growth is concentrated to higher-up branches. Trees in the understory tend to be lanky with widely spaced branches while trees in full sun eventually develop a broad-irregular to rounded crown and have dense branching. With lateral twigs lengthening year-after-year, and thus widening each division of a branch, overall branch structure becomes broad and rather planar. The weight of leaves and fruits on the weak lateral twigs cause twigs to become descending although overall branch structure is ascending. Wood is white, dense and heavy. Non-suckering roots are wide-spreading and shallow.
Photo 1: This tree, at a woodland margin and near a creek, has dense foliage. Upper limbs are ascending while lower limbs are horizontal to drooping. See tree structure in Photo 11. Photo – June 17.Photo 2: Trees have white, dense, heavy wood. This 4¼-inch cross-section with about 25 tree rings is from the base of a 30-foot tree. It was growing at woodland margin. Photo – November 20.Photo 3: This 6-year old tree has long, wide-spreading, reddish main roots along with fibrous rootlets. With a height of 4¼ feet tall, it has a ⅝-inch-diameter trunk at base. Photo – November 26.
New twigs, initially pale green and sparsely to densely soft-pubescent, become grayish-brown to reddish in winter and glabrous over several growth-years. Small white to tan, elongate lenticels (pores), becoming noticeable in the second growth-year, are set at 90⁰ to branch length. When the gray, fairly smooth branches/limbs achieve a diameter of 1± inch, the thin bark begins to fissure into narrow rectangular, flat-topped plates on which lenticels are no longer apparent. With continued expansion of branch/limb diameter, bark may exfoliate to such an extent that long, narrow, hardly-attached strips of bark hang loosely. The degree of exfoliation on mature trees varies by tree, but in general, bark on the lower portion of trunks remain relatively tight while that of the upper trunk and near-by portions of limbs develop the long loose strips.
Photo 4: Located by a perennial stream, this trunk has narrow rectangular plates of relatively tight exfoliating bark. Diameter at tree-base is 11 inches. Photo – March 18.Photo 5: Located in an open woodland, bark of this upper trunk (6 feet above ground) has loosely hanging bark strips. As shown to the left, gray lateral branches remain glabrous with lenticels still apparent. Photo – March 4.
Leaves are short-petiolate, elliptic to oval-lanceolate and have prominent, unevenly double-serrate margins from near leaf base to leaf apex. The teeth are sharply pointed. Leaf bases vary from narrowly rounded to shallowly cordate and may be oblique. From the leaf wide-point at mid-blade distally, blades gradually narrow in acute fashion to just below apices where blades often become abruptly acuminate resulting in narrow-pointed apices. The alternate leaves are 2-5 inches long (including a ¼+ inch petiole) and 1-2 inches wide. On a twig, smallest leaves are at twig-base. Leaves are dark green above and yellowish green below. Weakly arcuate pinnate secondary veins, in 12-16 slightly off-set parallel pairs, extend to tips of the larger marginal teeth. Upper and lower leaf surfaces feel soft and have variably appressed short pubescence. Pubescence on lower surface is denser and more villous, especially along veins and vein axils. Short petioles, also variably pubescent, twist leaf blades to best lighting so that twigs of a branch become oriented horizontally. Fall leaf color is yellow changing to crinkly tan before leaf-drop, with those of young trees and lower branches being somewhat marcescent (persistent).
Photo 6: Leaves have double-serrate margins and equally spaced pinnate secondary veins. Leaf bases are narrowly rounded to shallowly cordate and may be oblique (see large leaf on left). Photo – May 24.Photo 7: Leaves, feeling thin and smooth, are dark green above and yellowish green below. Short pubescence on both surfaces is appressed with that of the lower surface being concentrated at the junction of secondary veins with midrib. Photo – May 24.Photo 8: Leaves become yellow in fall and may persist as crinkly tan leaves into winter months. Photo – November 10.
Sharply pointed overwintering buds, round in cross-section with a pointed tip, are formed by several layers of imbricated glabrous bud-bracts. Buds, axillary to fallen leaves along the previous year’s twigs, are terminal and pseudo-terminal (both set in-line with twig) and lateral (set at 45⁰). Exposed portions of the tightly clasping buds are green in fall but change to a reddish brown into winter before becoming mostly green in spring as bracts unfurl. All leaves and catkins (aka aments) develop from buds that developed the previous growth-year. Separate staminate and pistillate catkins are on the same twigs and same tree.
Trees that are 20+ years old produce slim catkins of closely arranged sessile flowers along a central rachis (spicate inflorescence); sepals and petals absent. Narrowly cylindric staminate catkins grow from pseudo-terminal buds and lateral buds in mid-winter, with 1-4 catkins per leafless peduncle. Pistillate catkins, growing from terminal buds and lateral buds, appear in mid-spring. Flowers mature from catkin-base to catkin-apex. Pollination is by wind.
Early-growth staminate catkins are covered with tightly imbricated, brownish red, laterally rounded floral bracts with sharp apices. Floral bracts are regularly spaced along the rigid early-catkin. Approaching mid-spring, elongating catkins become pendulous and flexible as flowers separate slightly one-from-another. A mature flower consists of the cupped floral bract subtending a tight cluster of 3-14 stamens. The floral bract, yellowish green with a reddish tip, is broadly rounded with a sharp apex and fringed margins. Stamens consist of very short filaments topped with knobby, two-lobed anthers. Anthers open into tiny cup-like structures so that pollen is released to the breezes. A mature staminate catkin, bearing several hundred flowers, may be ¾-2¼ inches long on peduncles that are ½-1¼ inches long. Staminate catkins reach anthesis in mid-spring at the same time as pistillate catkins. Staminate catkins and their peduncle drop-off the twig shortly after pollen release.
Photo 9: Staminate catkins develop from pseudo-terminal buds (as shown at lower left) or lateral buds. The infructescence (at right) began as a catkin at the apex of an actively growing leafy twig originating, during the previous growth year, from a terminal or lateral bud. Pointed dormant buds are reddish brown. Photo – February 12.Photo 10: Pendulous staminate catkins are in sets of 1 to 4 on a single leafless peduncle. Branches of this diameter have glabrous bark and lenticels; not yet of sufficient age to have fissured bark. Photo – April 7.Photo 11: At this distance, although pistillate catkins and early leaves are present, staminate catkins dominate the tree’s appearance. Lower branches/limbs trend toward horizontal while upper ones are ascending. Photo – April 7.Photo 12: Staminate flowers, regularly spaced along the central axis, consist of fringed floral bracts subtending tight clusters of stamens with short filaments and knobby anthers. Photo – April 7.
Pistillate catkins occur at the growing tips of new leafy twigs; that new growth either lengthening existing twigs (from terminal buds) or forming new twigs (from lateral buds). Catkins have dense, silky (velutinous) loosely appressed pubescence. Early-growth catkins, ⅛-½ inch long, occur singly in mid-spring. Catkins are composed of elongate-triangular floral bracts with sharp apices. Floral bracts subtend an unseen side-by-side pair of pistils – each with a pair of long, red, wispy styles. Each pistil (ovary + style + stigma) is enclosed by a short, sack-like involucre, half the length of the ovary. Styles extend well beyond the floral bract where stigmas catch pollen carried by breezes. Floral bracts drop off once flowers are fertilized.
Once fertilized, involucre size increases greatly as they become large air-filled sacks. The ovoid involucres are flattened with the only opening being a small hole at the apex through which the styles extend. The enlarging pale-green catkins persist into fall when they dry to a dull brown, at which time they are 1-2½ inches long and ¾-1 inch wide. The tissue-thin involucres protect a single, free-standing nutlet attached at the bottom of the involucre. When nutlets are mature, involucres are to ⅞-inch long and ½-inch wide and as much as ⅛-inch thick at the nutlet. From mid-fall into winter, individual involucres drop off the rachis with the nutlet remaining attached at the involucre’s base. A few catkins may persist on trees into winter.
Photo 13: Pistillate catkins grow from the tip of new leafy twigs – either extending an existing twigs or developing new twigs at lateral buds. The two staminate catkins, on a single peduncle, are growing from a pseudo-terminal bud. Photo – April 8.Photo 14: The broad, yellow-green bud-bracts with reddish tips will soon drop off. The elongate round-tipped floral bracts are early deciduous. Each floral bract subtends two pistillate flowers, each with two wispy, red styles. Photo – April 8.Photo 15: The early-deciduous floral bracts have become brown; each having subtended two involucres. Villous pubescence of the involucres extends onto the rachis, peduncles and twig. Each involucre protects a single nutlet. Photo – May 24Photo 16: In mid-summer, the pale-yellow pistillate catkins stand out among the darker green foliage. Venation of leaves is off-set pinnate with secondary veins terminating at the larger marginal teeth. Largest leaves are at mid- to upper-twig. Photo – June 16Photo 17: Weight of catkins and leaves cause the low-strength twigs to bend down. In sunny sites, almost all new twigs terminate with a pistillate catkin. Photo – June 24.
Bases of the free-standing, oval nutlets are tightly attached at the interior-base on the sack-like involucre. With maturity, the light-weight and buoyant involucres individually drop off their rachises with their nutlet secured inside. Nutlets are dispersed by wind, flowing water and wildlife. Involucres disintegrate quickly. The smooth gray-brown nutlets, to about ¼ inch long and ⅛ inch wide, widest at mid-nutlet, have a rounded base and acute pointed apex. Involucres and nutlets are about the same shape although nutlets are narrower.
Photo 18: Involucres become dull brown as nutlets mature, with retention of pubescence. The free-standing nutlets attach at the interior-base of the sack-like involucre. Appressed hairs can be seen between secondary veins. September – 29Photo 19: The pistillate catkin, on right, grew from a lateral bud below a terminal bud which would have developed into a leafy twig extension with or without a pistillate catkin. The newly emergent pair of staminate catkins (on a single peduncle) grew from a lateral bud. Photo – December 15.Photo 20: In a sunny site, this tree produced thousands of pistillate catkins. Most higher-up catkins shed their involucres. Photo November – 14.
Hop Hornbeam trees that are 20+ years old have outstanding ornamental characteristics year-round. If already in a landscape, and not overly abundant, it would be an excellent tree to preserve. Seedlings can be established in a wide variety of well-drained soils in shady to sunny sites. It is a drought tolerant species. Those is shade will remain open, tall and graceful while those in sun will, over time, become dense and rounded. Lower limbs are spreading and self-shedding and if damaged the tree will grow with multiple trunks. Insects feed on the foliage and small mammals, birds (including turkey) eat the nutlets, but it is not a preferred food choice of deer. Due to its survival instincts and ready self-seeding, it may become “weedy” in some settings.
In Arkansas, the closest related species is Carpinus caroliniana, which has common names similar to those of Ostrya virginiana, including Hornbeam, American Hornbeam and Ironwood. Although having some similar to the same common names causes confusion, the two species are readily distinguished. Carpinus caroliniana 1) prefers moister soils, 2) has smooth trunks resembling musculature in an animal, 3) has smaller, glabrous leaves and 4) has nutlets that are subtended by 3-lobed spreading bracts.
Photo 21: Carpinus caroliniana has smooth, muscle-looking trunks. Another common name is Musclewood. Photo – March 8Photo 22:Carpinus caroliniana has smaller glabrous leaves and looser pistillate catkins and nutlets that are subtended by 3-lobed spreading bracts. Photo – September 29.
Ozark Sunflower (Helianthus silphioides) is a tall herbaceous perennial with large simple leaves and composite flowers with a purplish brown central disk and bright yellow ligules. The genus name is based on Greek words for sun (helios) and flower (anthos). The specific epithet notes that appearance of flowers and involucre are similar to those of rosinweeds in the Silphium genus*. Endemic to the U.S., most-widespread occurrence is reported from Arkansas, southern Missouri, Tennessee and northern Mississippi with less widespread occurrence in Oklahoma, Indiana, Kentucky, Alabama and Louisiana. In Arkansas, Ozark Sunflower occurs primarily in the Ozark Plateaus, Arkansas Valley, Ouachita Mountains and on northern portions of Crowley’s Ridge along with higher elevations of the West Gulf Coastal Plain. It is adaptable to various soil types, but prefers sunny to partially sunny, well-drained soils that range from moist to dry, such as in prairies and glades, along streambanks and woodland borders and openings. It is also known as Rosinweed Sunflower.
Plants, with many long ropy roots, have a knobby central rootstock that gradually widens near-surface as new stems sprout from bases of previous year’s stems. Erect stems, multiple for older plants, may grow to 8+ feet with a ½-inch-wide stem-base. Leaves along the stem’s lowest portion are opposite and become alternate a short distance below ascending, axillary branches along a stem’s upper third. Bases on the lower opposite leaves are clasping and encircle the stem while bases of alternate leaves that do not subtend branches are not clasping. The spreading branches, positioned from 30⁰ to 45⁰ off the stem, typically terminate with an open cluster (panicle) of flower heads. Branches range from 2+ feet long (lower ones) to those that are less than an inch in the congested apical portion of the inflorescence. From stem base into the branched portion of stems, leaf spacing along stems ranges from 3 to 5 inches (may be tighter at mid-stem where leaf size changes; see below) before decreasing to less than an inch near stem/branch apices. Most surfaces of stems and branches are uniformly covered with short hirsute pubescence. Pubescence decreases distally, becoming sparse-hirsute to absent (glabrous) along upper portions of stems and branches. Thereafter, shorter hirsute pubescence is found along the ultimate branches and stalks (peduncles) of individual flower heads. The solid-core stems and branches, terete without ribbing, are light green to mostly reddish, varying with plant growth.
Photo 1: Rootstock of this 3-year-old plant has two dead stubs of the previous year’s stems and 6 stems (partially shown) in current year. Sprouts at bases of stems will become stems for next year. Ropy roots grown from both the upper stem-level of rootstock and lower knobby stem-free portion. Photo – October 26.Photo 2: This first-year plant, shown at 9½ inches tall, reached a final height of 30 inches with a terminal cluster of 4 flower heads. Note opposite leaves and stem pubescence. Photo – August 10.Photo 3: New stems grow from bases of previous year’s stems of a plant in its third growth-year. Photo – March 8.Photo 4: At this early-growth stage, reddish color of stems extends onto petioles and into veins of new leaves. Plant at lower right is White Nymph (Trepocarpus aethusae). Photo – May 21.Photo 5: Clasping bases of lower, opposite leaves encircle stem. Dense short-hirsute pubescence covers the now light-green to reddish stem. Leaf bases are clasping and petioles are ciliate and winged (referenced below). Photo – October 14.Photo 6: Bases of mid-stem alternate leaves, below branches, are somewhat clasping. Stems (and branches) are terete without ribbing. Photo – August 9.Photo 7: Axillary branch development on this 29-inch-tall stem can be seen. At bottom of photo, leaf spacing is significantly tighter in the transition from the lower opposite leaves to upper alternate leaves. Entire plant is mostly green at this time. Photo – August 8.Photo 8: This close-up of developing branches shows hirsute pubescence extending from the stem onto the petioles and new branches. These lower stems may grow to 2+ feet long. Photo – August 9.Photo 9: At 5½ feet tall, change of leaf-size along the stems is apparent. Leaf spacing remains fairly consistent (except for the transition zone – see previous photo). Yellow composite flowers, to left, are of Woodland Sunflower (Helianthus strumosus). Photo – August 9.Photo 10: Pubescence of these upper reddish branches varies from sparse-hirsute to glabrous. Ascending branches, in sunnier open sites, are set from 30⁰ to 45⁰ off the stem. Photo – October 14.
Ovate cauline leaves are large below the branches [e.g., to 9 inches long (including a 2½-inch petiole) and 5 inches wide] while orbicular leaves subtending branches are much smaller [e.g., 4 inches long (including a 1-inch petiole) and 2½ inches wide]. Longest branches may have 1-2 opposite pairs of small leaves at about mid-branch which may subtend very short secondary branches with a few additional flower heads or a peduncle. Leaves have medium to dark green upper surfaces and light green lower surfaces. Leaves typically have a broadly cuneate apex and a rounded to truncate base abruptly contracted onto a narrowly winged petiole. The very firm, robust leaves have a blade-surface that undulates between principal veins. Flat to crinkly leaf margins are variously serrulate, to dentate to serrate – marginal cuts being small in comparison to the size of larger leaves. Margins of the smallest leaves may be entire. The short-hirsute pubescence on leaves makes them feel sandpapery (scabrous) across the upper and lower surfaces, although pubescence of the upper surface is less dense. Lower surface pubescence is more prominent along veins and continues along lower side of petioles. Stout ascending petioles have ridged, pubescent margins (ciliate pubescence) that are winged. Upper sides of petioles are grooved and glabrous.
Venation is arcuate-pinnate. Upper veins are impressed, with major veins having a raised center line. Lower veins are expressed, with the major veins elevated in round-relief. The most prominent pair of secondary veins is immediately above the petiole. Arcuate tertiary veins extend from secondary veins toward leaf-margin-side only. Main veins of upper surface are a lighter color of green or reddish while veins of lower surface are a paler green. Venation of petiole wings, extending from leaf blade, parallels the petiole.
Photo 11: Large, lower ovate leaves have broadly cuneate apices and rounded to truncate bases extending as wings along petioles. Venation is arcuate-pinnate. Photo – June 5.Photo 12: Upper leaf surfaces shown on left and lower surfaces on right. Leaves at the bottom of the photo are from unbranched lower portion of stem while upper leaves subtended branches above mid-stem. Lower-right leaf is 9 inches long and 5¾ inches wide. Photo – November 5.Photo 13: Underside (right) and margins of petioles have hirsute pubescence while the grooved upper side (left) is glabrous. Major veins on underside are elevated in round-relief. Veins of wings are parallel. Photo – November 5.Photo 14: Upper surfaces (left) and lower surfaces (right) are scabrous due to hirsute pubescence on both surfaces. Margins of left leaf entire to wavy. Photo – July 2.
Flower heads bloom from mid-September into late October. Stems have to 12+ branches on their upper ½ to ⅓. Branches terminate with panicles of 2-5 flower heads; with longer branches also having a few flower heads at mid-branch. The ascending, sturdy, pubescent peduncles, ½ to 1½ inches long, may have 1-2 elongate bracts positioned well below the flower head (see Photo 24). With the long branches and relatively small leaves, the overall floral array per stem is elongate and open. Flower heads, 2+ inches across, face skyward but do not track the sun.
Photo 15: These stems are 6 feet tall with a ½ inch base. Branches are along the upper ½ to ⅓ of mature stems. Floral arrays per branch are in open panicles. Photo – October 8.Photo 16: This stem has lower long branches and upper shorter branches terminating with several peduncles. The ascending, erect peduncles fix flower head faces skyward. Upper stem and all branches are mostly leafless. Photo – October 1.Photo 17: On left, the 2 lowest branches (13 inches long) of a stem. Apical portion of the same plant is on right. Peduncles are ½ to 1½ inches long. Photo – October 16.Photo 18: On left, this mid-portion of a branch bears leaves subtending a peduncle. On right, top portion of the same branch consists of the terminal flower head cluster. Hirsute pubescence can be seen. Photo – October 17.
Domed flower head buds are covered by stubby, broadly elongate bracts (phyllaries) in several imbricated series. Bracts have short hirsute pubescence on their exteriors, more notable along margins. With anthesis, phyllaries recurve to form a bowl-shaped involucre containing a flattened to convex receptacle. The firm phyllaries are about ¼ inch long and ⅛ inch wide.
Photo 19: Flower heads in bud are protected by broad, elongate, imbricated phyllaries in several series. At this stage, the long peduncles are not apparent. Photo – September 6.Photo 20: Exterior of phyllaries have minute hirsute pubescence with that along margins being more noticeable. This bowl-shaped involucre is ¾ inch wide and ½ inch deep. Photo – September 23.
The purplish brown central disk consists of tightly packed, fertile disk florets. The numerous tubular florets reach anthesis successionally from outer edge of the disk to the center. The pale green to translucent floral tubes (fused petals) have 5 triangular reddish-purple lobes that spread wide at anthesis. Florets, ¼+ inch long and 1/32+ inch wide, have 5 stamens (filament + anther) and a pistil (ovary + style + stigma). Stamens have elongated dark-purple anthers with connate side-margins which exsert as an elongated anther ring well above the corolla. Yellow pollen, released inside the anther ring, is pushed to the outside by the elongating yellow style/stigma. Thereafter, anthers shrink, and the stigma bifurcates to expose an opposite pair of elongated stigmatic surfaces, sharply recurved just above the corolla. Each disk floret is subtended, on their exterior side, by a thin, lanceolate pale-green bract.
The central disk is encircled by the bright-yellow, strap-like ligules (aka laminae or rays) of infertile ray florets. Ray florets have an ovary but lack style/stigma and stamens. A flower may have 10 – 25 overlapping ligules in a single series. Ligules, about ¾ inch long and 3/16 inch wide, are oblanceolate with a pinched base and an acute apex, with several pleats extending their length. Lower side of ligules are slightly duller than upper side. As the final flower heads pass anthesis, heads, peduncles and stems/branches dry while the lower portion of the stems remain viable into mid-fall. If the weather remains favorable, limited secondary flowering may occur lower on the stem.
Photo 21: The composite flower heads have ray florets with bright-yellow ligules surrounding a purplish brown central disk of numerous, tightly packed disk florets. Photo – October 10.Photo 22: The tubular disk florets may be translucent with spreading reddish-purple corolla lobes. Receptacle is flattened to convex. Involucre is 7/16 inch wide and ⅜ inch tall. Inset shows an infertile ray floret. Photo – September 23.Photo 23: (Enlarged from previous photo) #1: Anthers within floral tubes. #2: Anther rings exserted above corolla with pollen being pushed out by emerging style/stigma. #3: Anthers shrinking as stigma emerges. #4: Bifurcated stigma just above corolla. #5: An ovule of a disk floret. White arrow – Subtending bract of a disk floret. Black arrow – Scale on ovary (see below)
Fertilized disk florets produce ⅛-inch-long and 1/16-inch-wide mottled, dark brown oblong achenes (aka cypselae in Aster family) with pinched side-edges. They have rounded bases and truncated tops each with two, narrow-lanceolate, weakly attached scales that are almost as long as the achenes. Outer lateral edges of the somewhat flattened achenes and the rim of the truncated tops are covered with minute translucent scales. Scales are on a thin covering which, as achenes mature, splits-off to reveal glabrous, plump achenes. In the dense dry head, bracts subtending individual disk florets becomes chaff that remains as achenes drop from the head.
Photo 24: Stem (right) and its branch (left) terminate with peduncles (arrows) that are terminal. The remaining peduncles are axillary to subtending leaves. Lower peduncle on right bears a pair of elongated bracts well below the flower head. Peduncle on far-left is 2⅛ inches long. Photo – October 24.Photo 25: Immature achenes have a thin covering topped with a pair of narrow-lanceolate scales and minute marginal scales (main photo). With maturity, the covering splits-off to reveal glabrous, plump achenes (inset photo). Squares are ¼ inch. Photo – January 20..
In considering Ozark Sunflower for a garden, note: 1) Number of stems increases from year to year and the rootstock gradually expands, 2) May self-seed freely, 3) Foliage and plant structure attractive and bold throughout the growth-year, 4) Stems may exceed 8 feet but remain erect, 5) Numerous yellow composite flower heads late in the growing season and 6) beneficial for wildlife, insects and arachnids. Suitable as a specimen plant in a sunny native plant garden with sufficient space or in prairie or natural settings. To restrict self-seeding, stems and branches can be topped soon after flowering.
Photo 26: The yellow flower heads provided a fertile hunting ground for this camouflaged Crab Spider (Misumena vatia?). Photo – October 5.
Fifteen additional species within the genus Helianthus occur in Arkansas. Ozark Sunflower can be distinguished by: 1) its large ovate lower leaves and small orbicular upper leaves, 2) winged petioles, 3) purplish-brown disk, 4) rounded involucral bracts with pointed apices and 5) mottled achenes with weakly attached scales.
Sweet Coneflower (Rudbeckia subtomentosa) of the Aster family (Asteraceae) grows to 3-5 feet tall and has entire to lobed leaves. The genus name honors “Olof Rudbeck the Younger”, a Swedish botanist*. The specific epithet is Latin for “somewhat hairy” to denote its leaf pubescence. Sweet Coneflower occurs in a broad area extending from western Louisiana to southern Wisconsin and from eastern Kansas to western Indiana. In Arkansas, it occurs primarily in the Ouachita Mountains, Arkansas Valley and Ozark Plateaus along with several counties at the southeast corner of the state. It grows in prairies, open woodlands, stream banks, and roadsides in dry to moist sites with various soils. Sweet Coneflower prefers mostly to partially sunny areas. Other common names are Fragrant Coneflower and Sweet Black-Eyed Susan because the crushed flowerheads having an anise scent.
This erect herbaceous perennial develops multiple stems from a compact rootstock producing stubby, rhizomatous roots encircled by growth rings. Single composite flowerheads, on long peduncles, terminate stems and short branches along with additional peduncles growing directly from uppermost leaf axils. A stem and its branches may bear 12+ flowerheads. Width of the terete stems, to about ¼ inch at their bases, gradually reduce to 1/16 inch at flowerheads. Stems have slight, closely spaced ribs extending from their bases to the flowerheads. The straight stems, branches, and peduncles are erect to spreading. Very short, spreading to ascending, hirsute pubescence extends from stem base to the flowerheads – decreasing distally with age.
Photo 1: Stubby rhizomes grow from bases of old stems and directly from the rootstock. Remnants of an old stem of this 3-year old plant can be seen at center of the rootstock. Growth rings encircle rhizomes. Photo – September 27.Photo 2: Mature plants have multiple stems. Stems, along their lower portion, have large, ascending, lobed leaves. Slight ridges extend from stem base to the flowerheads. Photo – May 12.Photo 3: Straight stems and branches bear composite flowerheads on long, straight peduncles. Stem on right is 3¾ feet tall. Photo – August 13.
Petiolate leaves, with compound and simple shapes, have a medium green adaxial surface and pale green abaxial surface with whitish principal veins. Well-spaced secondary veins are recessed above and strongly expressed below. Adaxially, the blade surface between minor veins is puckered. Adaxial leaf surface and leaf margins have minute, hirsute pubescence while abaxial surface has dense slightly longer hirsute to short-pilose pubescence, especially on principal veins. Expanded bases of petioles are clasping – more so on lower leaves.
Photo 4: This unbranched stem (shown in 3 segments) has composite flowerheads on long peduncles. Large, petiolate leaves have compound and simple shapes. Peduncle of right flowerhead is 4¾ inches long. Photo – September 11.Photo 5: Abaxial side of leaves is pale green (left) while adaxial side is medium green (right) with whitish principal veins. Veins are well spaced. Photo – July 6.Photo 6: Adaxial side of leaves has short hirsute pubescence. Veins are recessed. Photo – July 6.Photo 7: Abaxial side of leaves bears appressed hirsute pubescence on blade fabric and spreading pilose pubescence along principal veins. Veins are strongly expressed. In photo, leaf tip is toward top of photo. Photo – July 6.
Ascending lower leaves are variously lobed with three primary lobes – a lateral pair of deeply cut lobes and a larger deeply cut terminal lobe. Leaf size is to 9 inches long (including a 3-inch petiole) and to 4½ inches wide. Secondary lobes, ascending in plane of a leaf, are elliptic to broadly elliptic with a tapering base and acuminate tips. Tertiary lobes, spreading in the plane of a leaf, tend to be finger-like. Primary lobes may be cut close to leaf rachis so that the rachis becomes winged – wing width tapers proximally. Leaf margins vary from entire (mostly on rachis side of lobes) to shallowly toothed to shallowly crenulated. Secondary venation varies from arcuate for broad lobes to parallel-arcuate for finger-like lobes. Secondary veins trend toward tips of leaves and lobes. Lowermost leaves drop-off with development of the upper stalk, especially with drying soil.
Ascending upper leaves are unlobed with elliptic to ovate shapes and with rounded bases and acuminate tips. A few leaves between lower-lobed and upper-unlobed leaves may have a single lateral lobe. For the unlobed leaves, leaves are to 3½ inches long (including a ¼-inch petiole) and 1½ inches wide while uppermost leaves are about 2¼ inches long (including a 1¼ inch petiole) and 1⅛ inches wide. Uppermost leaves of a flowering stem subtend either a branch (with leaves and 1+ flowerheads) or a peduncle. Peduncles, to 8 inches long, may bear 1+ leafy, sessile, lanceolate bracts as small as ⅜ inch long and 1/16 inch wide. All lobed and unlobed leaves are alternate and have the same color, margination and vein pattern.
Photo 8: With this stem’s inflorescence at bud-stage (hidden in photo), unlobed upper leaves continue to grow. Lobed leaf on left is 4¼ inches long and 2½ inches wide. Slight ribs can be seen along stem. Photo – June 27.Photo 9: At flowering, these elliptic to ovate upper leaves are firm with a puckered surface between minor veins. Two peduncles extend off the photo. Photo – September 24.Photo 10: Lower leaves (3 on left) have 3 primary lobes with the largest leaf having secondary and tertiary lobes. Leaf second from right has a single lateral lobe while the leaf on the right is entire. Leaves are positioned proximal to distal (left to right). Petioles have clasping bases. Photo – July 26.Photo 11: This stem has three peduncles of which the central peduncle terminates the stem while the other two are axillary. Peduncles may bear one to several small sessile leaves (bracts). Photo – September 11.
The inflorescence develops in mid-July with flowerheads in bloom from late July into late September. Flowerheads, to 3 inches wide, have a purplish brown central disk composed of numerous tightly packed, fertile, tubular florets surrounded by 16± sterile yellow ray florets. When in bud, the rounded tops of disk florets are closed by 5 stubby, triangular lobes. Florets reach anthesis successionally from the outer edge of the central disk to the center in circular fashion as lobes spread wide. Florets, about ⅛-inch long and 1/16 inch wide, have 5 stamens (filament + anther) and a pistil (fertile ovary + style +stigma). Florets have purplish brown upper portion and pale green hidden portion. Stamens and style/stigma are purplish brown. Stamens, adnate at base of corolla tube, have connate anthers which form an elongate ring which rises above the corolla. Yellow pollen is released inside the anther ring. As the style/stigma pushes through the anther ring, pollen is pushed outside and anthers shrink as the stigma bifurcates to expose an opposite pair of elongate stigmatic surfaces which recurve just above the corolla. Each disk floret is subtended, on the exterior-side of the central disk, by a thin, lanceolate green bract. These bracts remain shorter than the florets.
Ray florets have strap-like ligules (aka laminae) that first appear as a green finger extending from the margin of the central disk. Becoming bright yellow, ligules are oblanceolate with a pinched base forming several pleats extending to a rounded apex. Abaxial side of ligules bears sparse to dense minute pubescence. Rays, in a single series, attach to infertile ovaries.
Photo 12: Flowerheads are at various stages of development. Disk florets reach anthesis inward from outer edge of the disk in circular fashion. Green finger-like ligules of ray florets become bright yellow. Photo – July 30.Photo 13: Flowerheads are on long peduncles that terminate stems and branches or grow directly from uppermost leaf axils. Photo – August 5.Photo 14: Exserted anther rings of disk florets can be seen extending above the disk along with yellow pollen pushed out by the emerging stigmas. Emerged, recurved stigmas can be seen. Photo – July 30.
Flowerheads have a conic receptacle and a flat-bottomed involucre of closely spaced to overlapping lanceolate to broad-lanceolate bracts (phyllaries) in 2 to 3 series – those in upper series spreading while those of lower series down-turned. The firm bracts (to ⅜ inch long and ⅛ inch wide) are pale green with dense, appressed, minute pubescence on their exterior and margins with the pubescence extending onto the peduncles. When disk florets have passed anthesis, the central disk becomes dark brown before ray florets whither and head dries while remainder of plant remains viable.
Fertilized disk florets produce ⅛-long dark brown, 4-sided, narrow, conic achenes (aka cypselae in Aster family) with a truncate top rimmed with minute bristles (pappus). In the dense dry head, the bracts subtending disk florets becomes chaff that remains while the achenes drop from the head.
Photo 15: The involucre has a flattened bottom bearing pointed bracts in 2 to 3 series. This flowerhead, including the pleated ligules, is 2 inches wide. Photo – August 21.Photo 16: Tightly packed disk florets attach to a conic receptacle. As shown, disk florets have passed anthesis. Ligules, ovules removed, were detached from the disk. Photo – September 3.Photo 17: Ray florets are shown with their infertile ovules. Disk florets, subtended by a green lanceolate bracts, have a purplish brown upper portion and whitish lower portion above white fertile ovules. Photo – September 11.Photo 18: With disk florets having completed anthesis, the now-spherical central disks become dark brown. Photo – September 24.Photo 19: Crushed flowerheads separate into dried corollas of disk florets, achenes (see arrow) and other parts. Crushed dried flowerheads have an anise scent. Photo – September 26.
Sweet Coneflower is a good choice for most garden styles where the site is mostly sunny with well-drained soil. With its modest size, this perennial has interesting leaf shapes and showy composite flowerheads with bright yellow ligules. Flowerheads persist for a month or more in mid to late summer. The number of stems increases from year to year but plants are not aggressive invaders. Plants provide pollen and nectar to insects and seed for birds and small mammals.
In addition to Sweet Coneflower, 9 additional species of the genus occur in Arkansas – all with yellow composite flowerheads. Only 2 of the 9 species have lobed leaves; namely, Brown-Eyed Susan (Rudbeckia triloba var. triloba) and Cut Leaf Coneflower (Rudbeckia laciniata var laciniata). Sweet Coneflower can be identified by its perennial nature and larger flowerheads as compared to the annual much-branched Brown-Eyed Susan with small flowerheads, and by its compact clumping habit and pubescence as compared to the clonal perennial Cut Leaf Coneflower with glabrous stems and leaves and which favors significantly moister habitats.
*The genus name, established by Carl Linnaeus (who developed the binomial nomenclature in the 18th century) to commemorate his professor “Olof Rudbeck the Younger”. “Olof Rudbeck the Younger” is the son of Olaus Rudbeck (aka “Olof Rudbeck the Elder”), both prominent Swedish scientists and botanists. For a summation of their accomplishments see: Olaus Rudbeck – Wikipedia and Olof Rudbeck the Younger – Wikipedia.
Article and photographs by ANPS member Sid Vogelpohl
Common Evening Primrose (Oenothera biennis) of the Evening Primrose (Onagraceae) family is a large edible plant noted for its historic and current-day medicinal uses. The genus name is believed to be based on Greek words for “wine” (oinos) and “seeker” (thera). The specific epithet refers to the plant’s typical biennial life cycle, but plants may also be winter-annuals. Occurrence is widespread across the eastern half of the U.S. along with scattered occurrences across the remainder of the U.S. Native to eastern North America, it has been introduced into many temperate and subtropical areas around the world. In Arkansas, occurrence is statewide. Preferred habitats are sunny sites with dry to mesic sandy soils in prairies, glades, rights-of-way and disturbed land.
Photo 1: These winter-annuals grow in a sunny glade on a rocky, south-facing slope. Photo – August 8.
Winter-annual plants have branched taproots while biennial plants have carrot-like taproots*. Early in their first growth-year, biennials and winter-annual plants, have a rosette of basal leaves. Basal leaves, to 4-8 inches long and 2 inches wide, have off-set pinnate venation. Basal leaves, all with short to long petioles, are medium green to reddish (in cold temperatures) with white midribs. Tapering leaf bases extend onto petioles. Margins are mostly entire but, later, may show marginal features of stem (cauline) leaves – – see below. The elliptic basal leaves of winter-annuals drop off with stem growth. Early basal leaves of biennial plants are also elliptic but become long-spatulate to long-lanceolate during the first growth-year and remain until stem growth in the following spring.
Photo 2: Winter annuals have branched taproots. This plant had a height of 4 feet 10 inches (central root bent for photo – see arrow). Base of stem is ½ inch wide. Photo – August 11.Photo 3: Germinating over winter, these winter annuals developed into the flowering plants shown in Photo 1. Basal leaves drop off with stem growth. Photo – February 12.
Cauline leaves, oblanceolate to lanceolate, are to 5¼ inches long (including ½ inch petiole) and 1¼ inches wide. Leaves are arranged spirally on a terete stem. Firm leaf blades, fabric fairly flat to rumpled, are slightly ascending and slightly up-folded along midrib. To varying degree, tapering blade-bases extend onto petioles. Off-set pinnate veins, rather obscure above and prominent below, extend to near leaf margin where they align with one another and continue toward leaf apex. Upper and lower leaf surfaces have puberulent pubescence with that of the underside being denser. Upper sides of leaves are medium green while lower sides are a fuzzy-looking light green with midribs and petioles being a pale green. Margins of smaller leaves are entire while those of larger leaves are shallowly toothed to undulating with the teeth being blunt. Axillary buds that do not develop into branches often appear as very short stems with a few miniature leaves. With drying soils, lower cauline leaves drop off and upper leaves wilt until revived with renewed moisture.
Photo 4: With stem growth, leaves become oblanceolate to lanceolate and basal leaves drop off. Secondary veins are off-set pinnate. Leaf blades taper onto petioles. A winter annual shown. Photo – April 13.Photo 5: Lower pair of leaves is from below inflorescence. Upper pair of leaves subtended a branch. Upper and lower sides shown. Leaves were removed from the 2⅛-inch stem segment. Parts from a winter annual. Photo – August 12.Photo 6: At this stage, branches have not developed. Ascending leaves are slightly up-folded along midribs. A winter annual shown. Photo – May 12.Photo 7: Leaves, arranged spirally, have margins varying from entire to shallowly toothed to undulating. Some leaves have been nibbled by insects. A winter annual shown. Photo – August 27.Photo 8: Axillary buds that do not develop into branches often appear as very short stems with a few miniature leaves. A winter annual shown. Photo – August 27.
Stems, 3-6 feet tall with a base diameter of ½+ inches, may lack branches or, for more robust plants, have several to a half-dozen lower to mid-stem “primary branches” that are to 3+ feet long. Additionally, shorter branches, to 1 foot long, may occur along the distal portions of stems and primary branches. The terete, straight, solid-core, rigid stems and strongly ascending primary branches are initially pale green, becoming reddish-purple. Lower portions of stems and primary branches become tan to brown with the epidermis of more proximal portions splitting and exfoliating to varying degrees. Stems and branches are variously hairy with a dense mix of long hairs, hairs with reddish glandular bases (pustules) and short appressed hairs.
Photo 9: Primary branches are straight and ascending. Stems and branches become reddish-purple in the plant’s preferred sunny habitat. A winter annual shown. Photo – June 23.Photo 10: This still-growing plant is 4 feet tall with branches that are to 3½ feet long. Shorter branches develop along distal portions of the stem and larger branches. A winter annual shown. Photo – August 14.Photo 11: Stems are variously hairy with a dense mix of long hairs, hairs with reddish glandular bases and short appressed hairs. Also, see stem pubescence in Photo 5. Photo – August 12.Photo 12: With maturity, epidermis along lower portions of stems and larger branches splits and exfoliates. Lower leaves drop off as the season progresses, especially with drying soils. A winter annual shown. Photo – August 27.
The inflorescence consists of stout, erect, terminal spikes of axillary yellow flowers – – 1 flower per leaf axil. Flowers of biennial plants are in bloom in early spring of their second growth-year while those of annual plants are in bloom in mid-summer of their first (and only) growth-year. Flowering proceeds up-spike, with several flowers of a stem or branch in bloom at the same time so that bloom period extends for a month or more. The sessile flowers, arranged spirally, are longer than the internode separation (⅛ to ½ inch apart).
The erect flowers have 4 sepals, 4 petals, 8 stamens (filaments + anthers), a pistil (ovary + style + stigma) and a slender floral tube to 2¼ inches long. Sepals, ½ to 1¼ inches long, are lanceolate with free-standing, blunt tips. With anthesis, sepals spread open along their sides while remaining connected at their apexes before strongly reflexing against the floral tube. Often, several sepals remain connected at their apices. Greenish yellow sepals rim the greenish yellow floral tube. Bowl-shaped petals are broadly cordate with a slightly notched apex and a broadened, tapering base. Petals attach to the tube at the base of the sepals. Flowers, 1-2 inches in diameter, have faint (to humans) nectar guides and a slight lemon scent. The sturdy yellow filaments (⅞ inch long), undulating in uniform fashion to either side of the style/stigma, bear an elongate 2-lobed anther divided across tips of filaments; filaments also attached to the rim of the floral tube. The pistil consists of an exposed elongate ovary, a very long style (to 2¾ inches) and a stigma with 4 wide-spread cylindric lobes, each lobe to ¼ inch long. Exteriors (undersides) of lobes are covered by stigmatic surfaces and feel sticky. Light yellow pollen grains are loosely connected by strands of viscin – aiding pollen transfer by insects. Stamens and stigma do not extend beyond the rim of the corolla but, with the bowl-shaped corolla, are easily accessible to insects. Depending on and varying with weather conditions, the bright yellow flowers usually open in the evening and close the next morning.
While the corolla, stamens and pistils are glabrous; the floral tube and sepals have pubescence. Exterior of the floral tube has a mix of short appressed hairs and scattered longer, ascending hairs while the interior has dense, short pubescence. Exteriors of sepals are densely covered with appressed, equal length, puberulent pubescence while the interiors are glabrous.
Photo 13: With this branch’s terminal growth continuing, developing seed capsules can be seen along with 2 flowers that have closed and 1 that is poised to open. Floral tube of flower at left is 2⅛ inches long. A winter annual shown. Photo – August 12.Photo 14: This biennial plant, with rumpled leaves, shows vigorous stem growth in early spring. Site of this photo and next photo same as site shown in Photo 1. Photo March 27.Photo 15: Flowering of this biennial plant occurred in mid-spring. Photo – April 28.Photo 16: Inside of petals are shown on left, outside on right. The 2¾-inch style/stigma was removed from the floral tube (see red arrows) and separated from ovary. Each sepal has a free-standing, blunt tip (see white arrow). Photo – August 13.Photo 17: Sepals reflex against the floral tube. Several sepals often remain connected at their tips. Exteriors of sepals have minute appressed pubescence while interiors are glabrous. Photo – August 15.Photo 18: Stigmatic surfaces are on the outside of the 4 stigma-lobes while the inside (as seen from above) is smooth. Pollen grains are connected by viscin strands. Photo – August 15.Photo 19: Petals and sepals, removed for photo, attach to rim of the floral tube. The firm stamens, with elongate anthers divided across their tips, undulate in uniform fashion. Entire length of flower-part in photo is 1⅛ inches. Photo – August 13.Photo 20: With part of the floral tube removed, attachment of 4 filaments can be seen at lower right. Exterior and interior of tube are pubescent. Style extends upward. Photo – August 13.Photo 21: With floral tube extending to lower right, the hollow style can be seen extending into the ovary. Ovaries have four locules with 2 rows of aligned ovules. Nectar at base of floral tube. Photo – August 15.
Flowers are fertilized by nectar-seeking moths with long proboscises and small bees and other insects gathering pollen. With the dropping of flowers, the 4-locule ovaries enlarge to become hardened green capsules (to 1+ inch long and 3/16 inch wide). The terete capsules, initially broader at their rounded base, are composed of 4 compartments marked on the exterior by prominent grooves and 2 small-stubby apical knobs. When dry, the now straight-sided capsules split across their apices and separate along their side-margins while remaining attached at their bases. Spikes of uniformly shaped capsules are densely spaced with individual spikes 1+foot long; those of a full plant having a candelabra structure. Seeds are tightly stacked in two rows per compartment so that each capsule may have several hundred seeds. Dead plants and their capsules remain upright so that seeds are gradually dispersed over several months, aided by strong wind. The brown, irregularly shaped seeds have a greatest dimension of about 1/16 inch.
Photo 22: Capsules, densely pubescent, are composed of 4 longitudinal compartments separated by a prominent grove and terminating with 2 rounded, small-stubby lobes. Upper capsule is ¾ inch long and ¼ inch wide. Photo – August 12.Photo 23: Dried capsules split at their apices and along side-margins of the compartments. The style persists within gaping capsules. Pubescence is lost. Photo – December 3.Photo 24: The brown angular seeds, tightly stacked within capsules, drop out over several months. Squares equal ¼ inch. Photo – Nov 19.
In considering its suitability for a garden, Common Evening Primrose with its large size and bold branching structure, would certainly stand out. Due to its propensity to self-seed, for a more formal or small garden, removal of fruited spikes may be necessary. Probably best suited for naturalizing larger spaces. Plants provide pollen, nectar and foliage for moths and insects and seed for birds. Dead fruited spikes work well in dry arrangements. Historically, plants have been used for medicinal and/or food uses, and the species is commercially cultivated for seed oil for medical uses and research. Food uses include boiled roots of biennial plants and foliage and flowers for salads.
At least 17 species or subspecies of the genus (in narrow circumscription; not including members of Gaura and Stenosiphon which are sometimes included) are reported in Arkansas. Other than Showy Evening Primrose (O. speciosa), all other species in the state (again, under narrow circumscription) have yellow flowers. Of the tall, yellow-flowered species, Common Evening Primrose has size and leaf-shape similar to the native Hairy Evening Primrose (O. villosa subp. villosa). Common Evening Primrose can be distinguished by being variously hairy with a dense mix of long hairs, hairs with reddish glandular bases and minute appressed hairs, as well as by green or yellowish sepals. Hairy Evening Primrose is densely and uniformly pubescent with minute appressed hairs and has red striped or flushed red sepals. A non-native, tall species of similar appearance, reported from Pulaski County, is Garden Evening (aka Large Flower and Red Sepal) Primrose (O. glazioviana) – distinguished by its distinctly red sepals and larger flowers.
Photo 25: Garden Evening Primrose has a height of up to 5 feet. (Photo taken outside of Arkansas.) Photo – July 17.
Another member of the genus that has been previously addressed in this series of articles is Sundrops (O. fruticosa).
*The branched taproot of a winter-annual is shown in Photo 2. For images of the carrot-like taproots of biennials, query “Oenothera biennis + roots + images”.
Article and photographs by ANPS member Sid Vogelpohl
Everybody is welcome to attend! Meeting registration is only $10 with no pre-registration required. Registration will begin at 5:00 PM on Friday, September 29th.
15 king rooms have been reserved at the reduced rate of $109.00 plus tax per night. Reservations must be received by September 8, 2023 to guarantee the reduced rate. Be sure to mention that you are with the Arkansas Native Plant Society when making your reservation. Rate includes free parking and free breakfast. Individuals are responsible for their own room and tax. All cancellations must be made 42 hours prior to arrival.
Dining Options: We will have a Potluck meal Friday and Saturday evenings. Bring a dish or just come and eat! There are also many dining options in the Little Rock areas near the hotel.
Field trips: Several field trips to local areas of top botanical interest will be scheduled for Saturday 8:30AM-5:00PM and Sunday 8:30AM-12:00PM:
We will offer something for everybody, whether you want to take it slow and easy or something more vigorous. You must sign up for field trips on Friday evening to allow for adequate logistical planning.
White-Leaf Mountain Mint (Pycnanthemum albescens) of the Mint (Lamiaceae) family is a tall, upright perennial forb with a strong minty scent and has an open, gangly structure. The genus name is based on Greek words for dense (pyknos) and flower (anthos) in reference to its flower clusters. The specific epithet is from a Latin word (albescentem) for “becoming white” in reference to the uppermost leaves and bracts. Its primary area of occurrence extends from the Florida panhandle, across southwestern Alabama, Mississippi (excluding the lowlands), Louisiana (excluding the lowlands), east Texas, east Oklahoma, south Missouri and Arkansas. In Arkansas, it occurs statewide except for some portions of the Mississippi Alluvial Plain. Habitats are variable from partial shade in open woods, to full sun in prairies, from pinelands to oak woodlands and from mesic to dry soils that may be sandy to rocky to clayey.
During summer months, new rhizomes grow from the sides of rhizomes that developed the previous growth year, near the current year’s stem. These smooth, white rhizomes have decussate nodes bearing rudimentary buds that do not develop unless the rhizome is damaged. In early winter, the growing tip appears as a new stem, old stems having died and began decaying. With growth of a new stem, the “umbilical” rhizome dies and a separate clonal plant with a retained portion of rhizome which becomes and develops wiry, fibrous roots. Colonies tend to be somewhat open and isolated one from another. The new year’s stem growth has purplish stems and ovate, petiolate, early-deciduous, purplish-green leaves; basal leaves are absent.
Photo 1: Red arrow indicates stump of the living rhizome. Previous year’s dying rhizomes are indicated by white arrows. Yellow arrow indicates current year’s 3½ foot stem. Green arrows indicate previous year’s dead stems on a dead portion of the rhizome. Plant has 6 new, white rhizomes. Photo – July 30.Photo 2: Springtime stems are purplish with ovate, entire (margins uncut) leaves. Note the squareness of stems. Photo – March 19.
Mature stems are square in cross-section with distinct corners and flat sides. The erect stems have widely spaced, opposite leaves with internode lengths to 4 inches that are fairly equal, decreasing nearing stem apex. Stem leaves subtend ascending to wide-spreading branches that may be from near-zero-inch long (only a pair of leaves is seen) to 8 inches long; lengths quickly shortening near stem apex. A 4-foot stem, with a base-width of ⅛+ inch, may have up to 8 axillary branch pairs (primary branches) along its upper portion. Primary branches, square along their proximal portions, have base-widths less than half that of stems. Primary branches have one to several opposite leaf pairs with axillary buds which may develop into very short secondary branches bearing a single leaf pair. Leaves along primary branches orient toward sunlight and become aligned along sides of the branches. Stems and branches are covered by soft, dense, spreading pubescence which decreases with age. Lower primary branches typically terminate with a leaf-pair while upper primary branches often terminate with flower clusters. Leaves, branches, and flower clusters at the same node tend to be about the same size. At the end of the growing season, the hollow stems die back to the rhizome and readily break off and mostly decay by late spring.
Photo 3: Axillary branches are already present. With further internode growth, these branches will be positioned about the middle of mature stems. Photo – March 19.Photo 4: Plants have an open, gangly structure. This isolated group of stems, source of the plant in Photo 1, are probably all clonal. Site is an open woods alongside a creek. Tallest stems are 4 feet. Photo – July 27.
The simple leaves of a mature stem are lanceolate to broadly lanceolate and to 3¾ inches long (including a ½ inch petiole) and ⅞ inch wide. Leaves of the branches are usually half that size. Leaf blades may taper onto petioles. The smallest leaves have entire margins while larger leaves’ smooth margins are interrupted on their upper half to two-thirds by 4-8 shallow teeth as blade width decreases to acuminate apices. Pinnate venation, recessed above and expressed below, is well spaced. Secondary veins, mostly opposite but may be alternate, extend from the mid-rib at about 45⁰ and become parallel to leaf margins as they fade. The lower end of secondary veins may trend along midrib, toward petiole. Leaves near the inflorescences (floral leaves, herein) are strongly whitened above and below while other leaves (green leaves, herein) are olive-green above and whitish green below, with midribs of floral and green leaves a lighter shade. Floral leaves have dense, white, appressed, matted puberulent pubescence on both surfaces. Green leaves have short hirsute pubescence above and minute, short-matted pubescence below along with relatively long marginal (ciliate) pubescence. Leaf pubescence extends onto the petioles where it transitions to the longer, spreading pubescence of the stem or branch.
Photo 5: Larger leaves have smooth margins that are interrupted by shallow teeth. These “green leaves” have an olive green upper surface and whitish green lower surface. Photo – July 5.Photo 6: Upper leaf surface has short hirsute pubescence and longer, spreading pubescence on leaf margins and axis of this stem. The small leaf pair at right-center is on a very short axillary secondary branch. Photo – July 5.Photo 7: Underside of branch shown in Photo 6. Opposite to alternate, pinnate, secondary veins roughly parallel leaf margins. Lower end of some secondary veins trend along the midrib. Leaf blades may extend partway along petioles. Photo – July 5.
From July into September, the inflorescence consists of terminal and lateral clusters on stems and branches. Single clusters, to ⅞ by ⅝ inch, are axillary to pairs of opposite leaves so that an opposite pair of single clusters, often, visually merge into a double cluster. Each single cluster is on a stalk that is ⅛ to ¼ inch long. Clusters (single and double) are broadly rounded when viewed from above and disk-like with a flat bottom and slightly convex top when viewed from the side. A single cluster is composed of 2-3 cymes consisting of one to several pedicellate flowers positioned between a lateral pair of opposing “arms” bearing multiple pedunculate flowers along a curved stalk. A final opposite whitish leaf pair subtends a double cluster with further divisions of arms and cymes being subtended by increasingly small leaf-like, spade-shaped, whitish bracts followed by linear to filiform whitish bracts which occur along and at the terminus of the cymes. Thus, double clusters are ringed by whitish leaves, leaf-like bracts, and bracts and clusters have a spiky appearance. Blooming flowers are seemingly randomly scattered across a cluster because pedicellate flowers bloom first, followed sequentially by the pedunculate flowers.
Photo 8: Lower in photo, a pair of opposite leaves are on a very short secondary branch from each axil of opposing leaves. At top of photo, the developing inflorescence is on the side of the branch with a tiny terminal bud in between the clusters. Photo – July 6.Photo 9: The 2 largest leaves subtend the developing inflorescence (an opposite pair of cymes) while the 4 smaller leafy bracts are part of the inflorescence; two bracts subtending each cyme. Photo – July 21.Photo 10: Other than the flowers themselves, all parts of the inflorescence including calyx bracts, along with the subtending leaf pair, have appressed puberulent pubescence. This cluster (excluding ring of leaves and bracts) is 3/8 inch by 5/16 inch. Photo – July 6.Photo 11: Opposite pairs of cymes seemingly merge into a single cluster. With the numerous bracts extending from each cluster, clusters have a spiky appearance. Photo – July 26.Photo 12: This divided cluster consisted of 3 cymes of which only 2 are shown. Red arrows indicate flowers on pedicels (left flower has died) and yellow arrows indicate flowers on peduncles. Calyxes are 2 lipped with 5 triangular lobes (see calyx above right pedicel). Photo – July 27.Photo 13: Divided cluster: #1 = ½ of cluster , #2 = ¼ of cluster and #3 = ⅛ of cluster. Bracts change from spatulate to filiform along and at the end of the arms. Photo – August 10.Photo 14: A close-up to show the similar “texture” of the puberulent pubescence that covers various parts of a cyme. The number of bracts within an inflorescence varies from cluster to cluster. Photo shows two pedicellate flowers on the backside. Photo – July 27.
Flowers have a white, wide-flared corolla consisting of a lower lip with a broad central lobe and 2 elongate lateral lobes and an upper lip with a single lobe. Purple spots are scattered across the lower lip with the greatest concentration being across the cupped central lobe. From the front, corollas are about ¼ inch tall and ⅛ inch wide across the lower lobe while the upper lip is about ⅛ inch long and 1/32 inch wide. Flowers are glabrous on the outside while throat is pubescent. Upper lip is positioned along a straight-line with the axis of the calyx while lower lip lobes curve downward sharply. Lips unite to form a tube that is inserted into a pale green, terete calyx with a widened top and pinched base. Calyces are 3/16 inch long and 1/16 inch wide. Calyces (see Photo 12) have 2 lips; an upper lip that is 2-lobed and a lower lip that is 3-lobed; sometimes all lips and/or lobes cannot be seen. Lobes are stubby-triangular. Calyces (as are pedicels, peduncles and adjoining stalks) are densely covered with white, appressed, puberulent pubescence.
Flowers have 4 stamens (filament + anther) and a pistil (ovary + style + stigma). The white filaments (adnate to the sides of the throat) and style are fine-thread-like. The elongate 2-lobed anthers, balanced at the filaments’ tips, are exerted from the corolla. The strongly exserted anthers change from white, to orange (with pollen release) to brown. The style, as anthers dry, extends slightly beyond the anthers and unequally divides slightly at its tip to expose 2 unequal stigmatic surfaces. The tiny green ovaries (too small to photograph) have 4 ovules which mature to 4 wheat-shaped, brown nutlets in the fall.
Photo 15: Flowers have a 3-lobe lower lip and a 1-lobe upper lip. As shown, anthers change from white, to orange to brown. A divided stigma is silhouetted at upper left. Photo – September 13.Photo 16: Throats are filled with dense pubescence. Calyx lobes are stubby-triangular. Photo – August 10.Photo 17: As clusters dry, numerous nutlets are easily shaken from calyces. Photo – November 20.Photo 18: Tiny brown nutlets are wheat-shaped. Squares = ¼ inch. Photo – November 20.
In regards to gardening, considering its gangly appearance during most of the growing season, White-Leaf Mountain Mint may be best suited for a naturalistic garden. The near-inch-wide flower clusters have numerous tiny flowers which appear delicate when viewed up-close. White leaves and bracts associated with the inflorescence causes clusters to be showy. Plants do not seem to be aggressive spreaders, either by root or seed, but is easily propagated by rooted rhizomes. It has a fine minty scent when touched and provides nectar and pollen to insects for a month or more. White-Leaf Mountain Mint is not a preferred food by deer.
Photo 19: Flowers provide nectar to butterflies, including this Northern Metalmark (Calephelis borealis). Photo – August 4.
Other species of Pycnanthemum that occur in Arkansas are: Short-Tooth or Clustered Mountain Mint (P. muticum), Hairy Mountain Mint (P. pilosum), Slender or Narrow-Leaf Mountain Mint (P. tenuifolium) and Virginia Mountain Mint (P. viginianum). White-Leaf Mountain Mint is most similar to Clustered Mountain Mint, but White-Leaf Mountain Mint can be distinguished by its lanceolate to broadly lanceolate leaves and flower clusters that are more loosely arranged with noticeable, interspersed bracts. Additionally, bloom period of Clustered Mountain Mint is about a month earlier.
Photo 20: Photo shows the inflorescence of Clustered Mountain Mint (P. muticum). Photo – June 24.
Article and photographs by ANPS member Sid Vogelpohl
Arkansas Native Plant Society 