Arkansas Native Plant Society

Know Your Natives – Yellow Leafcup

Posted on by

Yellow leafcup (Smallanthus uvedalius), formerly Polymnia uvedalia, of the Aster (Asteraceae) family is a tall herbaceous perennial with very large petiolate leaves. The genus name honors John Kunkel Small, American botanist and author of Manual of the Southeastern Flora, 1933–still the most recent comprehensive floristic treatment of the Southeast. The specific epithet is from Latin for “stands out”. In the U.S., it is found from central Texas to southeastern Kansas to Michigan to New York, thence southward to the Atlantic and Gulf Coasts. In Arkansas, it is found statewide. Yellow leafcup is the only species of the genus Smallanthus occurring in North America. Other common names include bear’s-foot and hairy leafcup. Its habitat includes moist soils in partially sunny thickets, woodlands and fields.

Photo 1: In this late February photo, new stems arise from a clump of tuberous roots. Previous year’s stem lies on the ground.

Yellow leafcup, when fully mature, routinely reaches 4 to 5 feet tall, but may be up to 10 feet tall. Roots are a tight clump of elongate, irregular fibrous to tuberous roots. The stout, round (terete), erect stems may have a lower-stem diameter of an inch or more. Main stems sparingly develop secondary stems which may be 4+ feet long. The hollow (fistulose) stems bear opposite decussate leaf pairs (rotated 90 degrees from each adjacent pair). Petioles of larger leaves widen at their bases such that stems have “rings” at those nodes. Short, cup-like or two-lobed, leafy cauline appendages (stipules) grow between the opposite petioles on these rings. Moving up-stem, the diameter of the stem noticeably reduces in cross-sectional size from one pair of leaves to the next, in telescoping fashion. Stems have three rounded, longitudinal ridges extending below petioles, but ridges are flattened along lower portions of larger stems. Stems, a light green color, are densely covered with uniformly short pubescence that varies from hirsute (bristly) lower on stems to puberulent (soft) within the inflorescence. Main and secondary stems, along their upper portions, bear floral branches (to 10 inches long) from axils of leaf pairs. In winter, dead stems break off at ground level where they continue to decay into the following year.

Photo 2: Stipules (leaf cups) grow from “rings” that connect petioles of opposite leaf pairs. Dense cauline pubescence extends onto petioles.

Leaves are variable in shape and size, but all are thin and flimsy with very short hirsute pubescence across the upper surfaces and mainly along veins on lower surfaces. With denser pubescence on the upper surface, which is hooked toward the leaf apex, the upper surface feels softly scabrous (rough). The upper leaf surface is a medium green while the lower leaf surface is lighter green with the veins being lighter still. The unusual leaf venation comprises three major veins, two of which join the midvein above the base of the leaf blade. These three primary veins serve as midveins for the three large, irregular lobes. Veins of the upper surface are depressed and those of the lower surface are expressed.

Large lower cauline leaves, to 12+ inches long and 8+ inches wide, have two primary lateral lobes and a terminal lobe. These main lobes, ending with broadly tapering tips, have several secondary tips and irregular undulations, but otherwise margins are smooth. Although leaf blade tissue narrows abruptly below the lateral lobes, leaf tissue in the form of jagged “wings” often continues down the sides of the petiole, especially on larger and lower leaves, stopping an inch or so from the stem or extending to the stem. The upper surface of a petiole becomes deeply grooved toward the stem. Upper cauline leaves become smaller and less lobed to unlobed, with a tapered apex and a broad base above a winged petiole. Within the inflorescence, small broad leaves may have five spreading tips and short petioles, further reducing in size up-stem to linear and sessile.

Photo 3: Leaves decrease in size and become less complex up-stem. Small linear leaves occur within the inflorescence.

Yellow leafcup produces composite flower heads in mid to late summer that are positioned around the upper perimeter of the plant. Several uppermost cauline leaf pairs of main and secondary stems each produce two acutely-spread, axillary floral branches with or without a central branch. These lateral and central branches, depending on plant maturity and environmental factors, may bear additional opposite linear leaves which, in turn, support further stem division within the inflorescence. The “highest” or most distal cauline leaf pair subtends erect peduncles (stalks of inflorescences) to 1½ inches long that bear several clusters of flower heads on weak pedicels to ¾ inch long. Upper portions of stems/branches, peduncles and pedicles are equally covered with dense, fine pubescence.

Clusters of two to five flower heads occur in equally sized opposite pairs. Along with a terminal cluster, up to six or so lower opposite-branched pairs may occur in corymb-style arrays. Clusters and individual flower heads are subtended by small opposite linear leaves, except the terminal head does not have a subtending leaf. Flower heads and clusters tend to be crowded together. A multi-stemmed mature plant may produce several hundred flower heads.

Photo 4: Display shows a stem (or branch) that originally terminated with a single flower head (at lower center). A pair of floral branches grew from axils of the lower large leaves and another pair grew from axils of small linear leaves within the inflorescence.

The composite flower heads, to 2 inches wide and facing outward or downward, consist of up to a dozen yellow pistillate (fertile pistils but no stamens) ray florets and 50 or so staminate (fertile stamens and infertile pistils) yellow disk florets based on a 1/4-inch wide receptacle. Elliptic pleated ligules of ray florets (to about 5/8 inch long), pinched at their bases, have two or three stubby apical lobes. Styles of ray florets with bifurcated stigmas are also yellow. Disk florets have flared corollas with five triangular lobes that join to form a stalked, skinny and campanulate (bell shaped) tube. Corollas of disk florets enclose a tube of five purple anthers that produce yellow pollen. The anther tube hides a white style with an undeveloped stigma, so that rudimentary ovules do not develop into seeds.

Photo 5: Flower heads shown are at various stages of development: a bud at lower right, heads at anthesis at lower left and upper right and a head with maturing fruit at upper left.

Flower heads have a convex receptacle from which florets and receptacular bracts grow. Each ray floret and disk floret is subtended by a bract positioned away from the center of the flower head. Bracts that subtend ray florets are broadly triangular with acute tips (3/8 inch long and 2/8 wide) and are cupped so that the ovaries and developing fruits are tightly enveloped. Bracts subtending ray florets, also triangular, are smaller and narrower. Four to six leafy, triangular and longitudinally pleated involucral bracts (5/8 inch long and ½ wide), which loosely covered the flower head while in bud, subtend flower heads. The pubescence of receptacular and involucral bracts is not noticeable without magnification.

Photo 6: Display of a divided flower head along with two separated disk florets. Note convex receptacle, purple anthers topped with pollen and large ovules of ray florets. Note subtending receptacular and involucral bracts.

With fertilization, ray florets produce hard, slightly flattened, ovoid achenes. Achenes, about ¼ inch long and wide, are almost circular when viewed from a flattened side. The achenes are smooth and purplish to dark brown.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Wildflowers, Yellow | Tagged Asteraceae, Smallanthus, Smallanthus uvedalius, Yellow Leafcup | Leave a comment

Know Your Natives – White Leafcup

Posted on by

White leafcup (Polymnia canadensis) of the Aster (Asteraceae) Family is a coarse, short-lived perennial. The genus name is in reference to the Greek Muse Polymnia (also spelled Polyhymnia), goddess of music, song and dance. The specific epithet refers to the plant’s occurrence in Canada. In the U.S., its greatest concentration occurs in eastern Oklahoma across Arkansas and Missouri and, from there, scattered north into Minnesota to Vermont as well as south into northern Alabama. In Arkansas, it is primarily limited to the Interior Highlands (Ozark Mountains, Arkansas River Valley and Ouachita Mountains). Other common names include small-flower leafcup, white-flower leafcup, white bear’s-foot and Canadian leafcup*. White leafcup’s habitat preference is light to medium shade in consistently moist, well-drained, rocky deciduous woods, ravines and talus slopes.

White leafcup is an herbaceous plant with several stems from 2 to 5 feet long that grow from short fibrous roots. Plants are mostly erect and may have a few lower branches along with shorter branching in the inflorescence. Lower branches grow straight from the main stems at a wide angles. Terete stems and branches are fistulose (hollow) and larger stems have noticeably longitudinal, rounded ridges. Stems and branches vary from light green to purplish with light green dominating on younger portions of branches and along shady sides of smaller stems and branches. Stems and branches are puberulent (covered with fine short down) throughout the plant, with pubescence within the inflorescence becoming longer and glandular (sap at hair tips). The glandular pubescence causes upper portions of flowering branches to feel viscid (sticky). Leaves are opposite or the uppermost alternate. Leaf margins are narrowly turned-under (revolute).

Lower leaves, to 12 inches long and 8 inches wide, have two to four somewhat opposite deeply cut lobe pairs with irregularly large-scale serrated margins. The terminal lobe, lateral lobes and major secondary lobes have acuminate (gradually tapering) tips. The largest lobes may be 2½ inches long and 1 inch wide. The soft leaves, dull light to medium green on upper and lower surfaces, are puberulent on the upper surfaces and less so on lower surfaces. The upper half of the petioles have wings with the same characteristics as the leaf lobes, including irregular margins. Wings lower on the petioles/midribs are narrower. Petioles, to 4 inches long and rounded with flat tops, have short pubescence with longer scattered hairs along their edges. Pinnate venation is slightly suppressed on upper surface and strongly expressed on lower surface, with lower midrib of larger leaves standing in sharp, rounded relief. Crushed leaves have a strong lemony scent.

Photo 1: A young plant bearing the characteristic large ragged leaves of the species. Photo in mid-June

The bases of opposite leaves may be expanded and fused so that they wrap around the stem to form a leafy cup (the basis of the common name “leafcup”).

Leaves up-stem into the inflorescence become smaller, with shapes varying from hastate to broadly triangular. These small leaves may have entire (undivided) margins or shallowly crenulated margins with tiny tips that mark ends of tertiary veins. Smaller leaves do not have expanded bases and petioles are not winged.

Photo 2: Display showing large and smaller leaves and upper and lower surfaces. Small leaves at top have crenulated margins with tips. Note ribbed stem, purplish coloration and barely expanded leaf bases.

Flowering, consisting of composite flower heads, may occur from late spring into mid-fall over a two month period. Upper portion of branches bear several clusters of flower heads. Clusters are subtended, going from those lower to upper in the inflorescence, by small hastate leaves, to smaller triangular leaves, to even smaller lanceolate leaves and to tiny bract-like leaves. Each flower head in a cluster (except for terminal flower heads) is subtended by a short linear bract about ⅜ inch long and 1/16 inch wide. Flower heads are on weak pedicels to about ¼ inch long. Terminal flower heads of a cluster bloom first.

Photo 3: Stem and branches topped by clusters of flowerheads. Stems tend to be purplish.

Photo 4: In a shady open site, branches are especially long and low-angled. Some leaves and branches are opposite and some are alternate.

Buds of the flower heads are covered by involucral bracts (phyllaries) in two series, the inner slightly longer than the outer. Margins of phyllaries bear long, twisty and sticky hairs (viscid pilose pubescence). As florets mature, apices of phyllaries curve backward.

When the disk of the flower head is first exposed, its flat surface is covered by light green, pointed, elongate-triangular and concave bracts, which individually wrap around each disk and ray floret. Ray florets develop ligules that extend outward. Each disk floret opens directly upward. The first florets to reach anthesis are ray florets along with the outermost ring of disk florets followed incrementally by smaller rings toward the center of flower head. The width of flower head when ray florets are at anthesis is up to 1¼ inches. The round involucres are about ⅓ inch deep and wide.

Photo 5: Pubescence of branch, phyllaries and floral bracts can be seen. Note ligules just beginning to show on bud at upper left and leaf shapes of cluster on right.

Flower heads bear up to a dozen pistillate (no stamens) ray flowers and 25 or more light yellow staminate (pistils not functional) disk flowers. Ray florets have obovate, white ligules with pleated surfaces and three equal-size shallow, apical lobes and pubescent pinched bases. Ligules, about ⅓ inch long and broad, are sharply bent at their bases so that ligules flare outward. Styles of the ray florets are white with white bifurcated stigmas. Disk florets have pale yellowish-green flared corollas with five triangular lobes that join to form a skinny stalked tube. Corollas of disk florets enclose an exserted column of five light yellow stamens with yellow pollen. The column of stamens encircles a style with an infertile stigma based on a rudimentary ovary with ovules that do not develop.

Photo 6: Staminate disk florets produce pollen while pistillate ray florets bear bifurcated styles.

Photo 7: Display showing parts of a flower head that held eight pistillate ray florets, receptacular bracts that subtended the ray florets, two involucral bracts and a few staminate disk florets.

With fertilization, a flower head produces hard brown ovoid achenes. Achenes are about ⅛ inch long with rounded bases and three-angled apexes.

A second species of the Polymnia genus occurs in Arkansas, namely Cossatot leafcup (Polymnia cossatotensis). This species, endemic to Arkansas (five known sites in Polk and Montgomery Counties), is found on novaculite talus slopes. This annual species has heart-shaped leaves and flower heads with relatively small yellow centers of disk florets and usually two to three white ligules.

Peruvian daisy or quick weed (Galinsoga quadriradiata), recorded from seven scattered Arkansas counties, has flower heads similar in appearance to those of white leafcup. This non-native invasive species is a much smaller plant with coarsely toothed but unlobed leaves and occurs in open, disturbed areas.

The terms “small-flower” and “white bear’s-foot” are in contrast to structures in the closely related bear’s-foot or yellow leafcup (Smallanthus uvedalius), previously classified in the Polymnia genus. Bear’s-foot, a larger plant than white leafcup, has larger yellow flowers and broader leaves and is most often encountered on stream and river terraces.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, White, Wildflowers | Tagged Asteraceae, Know Your Natives, Polymnia, Polymnia canadensis, White Leaf Cup | Leave a comment

Know Your Natives – White Four-O’Clock

Posted on by

White four-o’clock (Mirabilis albida) of the Four-O’Clock (Nyctaginaceae) Family is an herbaceous perennial that blooms from evening into the next morning. The genus name is from a Latin word meaning “wonderful”. The specific epithet is from Latin for “whitish”*. Another common name is pale umbrella-wort, in reference to the plant’s large floral bracts. This plant occurs throughout the central and in scattered areas of the eastern U.S. In Arkansas, it is found across much of the Interior Highlands of the northwestern half of the state, as well as a few scattered occurrences in the sandhills of the Coastal Plain. Habitat includes dry to well drained prairies, glades, and openings in deciduous woods.

White four-o’clock develops several lanky, erect to leaning stems that grow from terete (round in cross-section), white (externally tan) rambling roots. Stems, growing from several shallow points of the root, are a yellowish-green to medium green and may have purplish streaks or blotches. Lower portion of larger stems becomes brown-fissured and persists into the next year. Stems may reach 4 feet or more tall, with a few scattered lower branches and many upper branches bearing inflorescences. Terete stems and branches have widely spaced swollen nodes from which leaves and additional branches and leaves grow. Stems and branches exhibit various degrees of pubescence, ranging from glabrous to puberulent (covered with fine down).

Photo 1: This young plant has several stems with the stem on the right bearing a floral bract (encloses flowers) near its apex.

White four-o’clock bears opposite, linear cauline (stem) leaves. Plants appear leafy early in the growing season but soon become open or even scraggly. Lowermost leaves may be 5½ inches long and ¾ inch wide while leaves approaching the inflorescence become increasingly small to tiny. While lower leaves have short (to ¼ inch) partially winged petioles, upper leaves are sessile. Leaves are entire (smooth margins) with a uniform width between their tapering rounded apices and wedge-shaped (cuneate) bases. Larger leaves are ascending and arched with a gentle up-fold along their midribs. Leaf venation is pinnate.

Photo 2: Display shows coloration of terete stems with swollen nodes and underside of a leaf.

Flowers bloom from early summer into fall. Inflorescences of young plants are axillary along the unbranched main stems. On multi-branched plants, inflorescences occur near the ends of branches. As flowers bloom, branch apices continue to grow to allow production of additional leaves and flowers. With a multitude of flowering branches, the upper portion of the plant may become twisty and intertwined.

A leaf axil produces a single spindly peduncle to about 5/8 inch long which supports a single calyxlike floral bract that typically bears three flowers. The loosely up-folded large ruffled bract hides three ovaries which appear topped by flower buds–actually the showy calyces still unexpanded. (There are no true petals in four-o’clock flowers.) As a flower approaches maturity, the flower expands and is exserted (see below) from the floral bract. Then, as the flower fades, it shrinks into a ball that withdraws back into the enclosing bract. Peduncles and bracts (joined as a single unit), at first light green to purplish and lightly to densely pubescent, open wider and become dry, light tan and tissue-thin when ovaries have matured into achene fruits. Dry bracts are up to 1 inch wide (when flattened). The peduncle-bract unit, now very lightweight, falls off with fruit still adhering. With sequentially up-branch detachment of peduncle-bract units, branches become naked except for pairs of “subtending” small leaves.

Photo 3: Flowers bloom near ends of branches as growth continues at their apices. As fruit-bearing, peduncle-bract units drop off, branches become naked except for small leaf pairs.

Flowers of any particular floral bract, typically 2-5, bloom and fade within several days. Fully opened flowers (versus those that do not open fully, as noted below) become exserted from the floral bract, displaying five light pink to rose, spreading, thin, deeply notched calyx lobes extending from a bowl-like base. Each calyx lobe is ½+ inch wide.

Flowers are perfect and about ½ inch across. Five long slender stamens and a long slender style have coloration similar to the calyx. Stamens and style are strongly exserted and may be in a central straight group or be widely separated and twisty. Stamens bear round masses of yellow pollen and the style has a white, round (capitate) stigma. Style, stamens and calyx are attached at the top of a single ovary, which is one of several ovaries attached to the floral bract.

Photo 4: Lavender calyx, stamens and style of this half-inch-wide flower are attached to top of one of three ovules within a floral bract.

In addition to flowers that open fully, some flowers open partially. With those, the stamens and style are slightly exserted outside the rolled-up calyx. Additionally, some flowers are apparently self-pollinating so that the buds do not attempt to develop (cleistogamous flowers). Viable fruits may be produced by flowers fully or partially open as well as by cleistogamous flowers. Often, some ovaries on a bract do not develop into viable fruit.

Photo 5: As a flower fades on the right, fruits attached to a lower floral bract (left) mature. Third object within bract is a drying detached flower.

The ovary of fertilized flowers changes from a light green color to whitish before drying and shrinking from about 3/16 inch long to form a single, dry, hard, oddly-shaped, yellowish-brown, one-fifth-inch-long fruit, an achene. The fruits are rounded in cross-section, elongate, and covered with rounded knobs (tubercles) along five longitudinal ribs and along sunken inter-rib areas (sulci). Fruits taper to broad rounded tops and small tapered bases (hot-air balloon shape). Fruits have a circular pattern at the apices where calyx, stamens and style were attached. Lines of spiky hairs cover the fruit. As fruit matures, light green floral bracts become more open and change to light tan to whitish as they become dry. These dry peduncle-bracts drop off with fruits still attached.

Photo 6: This floral bract, with attached peduncle and fruit, is poised to drop off. Note fruits’ texture, shape of bract and its five radiating veins. Black spot marks where a third fruit had been attached.

Photo 7: With floral bracts partially cut-off, this display shows fruits produced by self-pollination. An undeveloped flower bud at lower left.

Two additional species of the genus have been recorded in Arkansas. Wild four-o’clock (a.k.a. heart-leaf four-o’clock) (Mirabilis nyctaginea), which is native, is shorter and sturdier than Mirabilis albida and has larger cordate to triangular leaves. The inflorescences of Mirabilis nyctaginea occur in large, dense terminal clusters. Garden four-o’clock (a.k.a. marvel-of-Peru) (Mirabilis jalapa), native to South America, is also shorter and sturdier than Mirabilis albida and has larger trumpet-shaped flowers in various solid shades of red, pink, purple, yellow, white or may even be variegated (with potentially different colored flowers on the same individual plant).

Reference to “whitish” is not certain. Roots, immature fruit and dry floral bracts are all whitish.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Purple, Wildflowers | Tagged Know Your Natives, Mirabilis, Mirabilis albida, Nyctaginaceae, White Four-o'Clock | Leave a comment

Know Your Natives – Butterfly Pea

Posted on by

Butterfly Pea (Clitoria mariana) of the Pea/Bean (Fabaceae) family, the only species of the genus occurring in Arkansas, has large pea-shaped flowers. In the U.S., it occurs from New Mexico to Kansas, Nebraska, and Minnesota, east to New York and thence southward to the coasts. It occurs statewide in Arkansas. The genus name derives from the flower’s small keel, suggesting (to Linnaeus) the mammalian clitoris. The specific epithet refers possibly to the Virigin Mary or perhaps to the state of Maryland (although the type specimen was from Virginia, so this seems less likely). Another common name is Atlantic pigeonwings. Habitat includes sunny to partially shaded, well-drained pine or mixed woodlands or glades with acid soils.

Butterfly pea, a low-growing, trailing herbaceous perennial legume, has straight, slender stems and branches that grow from a small rough caudex and a long, slender, sparingly branched, spreading and tough root. Initial stem growth to 6 to 8 inches tends to be erect while ensuing growth becomes vine-like. Stems may reach 4 feet long. A stem may have two to five branches that ramble in various directions. Although branches are vine-like, without twining or tendrils, the plants sprawl along the ground or over and through other plants rather than climbing. Terete branches are yellowish green and glabrous. Ends of trailing branches in contact with soil may develop adventitious roots. Wiry dead stems remain over winter into the following spring.

Photo 1: New, erect growth of an established plant. Photo taken in late May.

Nodes, arranged alternately about stems and branches (hereinafter both are referred to as “vines”), are spaced from 1 to 2½ inches apart lower on the plant; however, spacing gradually decreases to being almost side-by-side toward the tips of the vines. Each node bears two outward pointing, stiff stipules that subtend the leaf, vine or inflorescence that develops from that particular node. Generally, a node bears a leaf which subtends a vine (sometimes very short) or inflorescence.

Photo 2: Later growth may become vine-like, but not twining or clinging to other vegetation. Root caudex is roughened by previous years’ deciduous growth. Photo, taken in late July, also shows several faded flowers.

Compound, trifoliate leaves, with slightly swollen petiole bases, have three oblong-lanceolate leaflets with smoothly rounded bases. Leaflets are widest below the middle, from where they gently taper to a rounded apex terminating with a pin-point tip (mucronate). Length of petioles (from vine to lateral leaflets) is about three times as long as the length of the rachis (from lateral leaflets to terminal leaflet). Petioles are straight and rigid from vine to lateral leaflets, from which point it may assume a down-trending direction, but still straight and rigid. Leaflets, with very short petiolules (stalks), have a dull, dark green upper surface and lighter green lower surface. Leaflets are noticeably folded along mid-ribs and have entire (smooth) slightly revolute (turned under) margins. Largest leaves lower on the plant may be 5 inches long (including petioles) and 4 inches wide. Largest leaflets may be 2½ inches long and 1+ inch wide with terminal leaflets being somewhat larger than laterals. A pair of acicular persistent stipels (the “stipules” of a leaflet), to about ⅛ inch long, subtends lateral leaflets and another pair subtends the terminal leaflet. Sparse short hairs may occur on lower side of leaves, especially along the midrib. Venation is pinnate, with secondary veins being weakly depressed on upper leaflet surface and expressed on lower surface.

Photo 3: A pair of stipels subtends lateral leaflet pairs and another pair subtends terminal leaflets. Leaflets are oblong-lanceolate.

The inflorescence, at mid-summer, is subtended by a leaf at nodes along most of the vine beyond the lower erect portion. One to three flowers may share a peduncle and the same node may also support a second peduncle or a new vine. Flowers are on short pedicels that “knee-off” short peduncles at which point another pair of stipules is located. Buds nearing anthesis are long, skinny and pointed. Many flower buds do not develop fully.

Photo 4: At nodes, various combinations of growth occur that involve new vines, leaves and flowers. Note skinny pointed flower bud at upper right and long, lobed calyx of flower behind.

Flowers are pea-like with a large banner (or standard) and smaller wings and keel. However, unlike pea flowers, the banner is disposed downward (flowers resupinate) rather than erect. Butterfly pea flowers have a widely flared, deep-veined banner and a pair of upward-projecting, relatively small-eared, curvy wings at center of banner which enclose a pair of smaller petals that form the keel. The banner, with a widely flared “bowl” shape up to 2 inches wide, has purple streaking in its deepest portion along with a centered whitish patch toward the banner’s outer edge. The banner is folded along the middle and notched at the apex. The exposed portion of the wings loosely encloses a down-curved keel, with the keel’s open side below. Wings and keel petals have narrow stalk-like basal portions (claws), with claws of the keel being longer and more narrow than those of the wings. Petals of the keel and wings are adnate (joined) at about their mid-point and not joined above or below that point. The hood-like keel hides ten stamens, of which nine are fused to form a down-curved tube. The tenth stamen is free, that is, not fused to the other nine. The stamen tube encloses a down-curved pistil, except for its slightly exserted stigma. Keel petals have a folded-over margin and an internal flange which forms a downturned “channel” which tightly grasps the stamen tube. Flowers have a long flattened calyx tube with five triangular lobes, subtended by two small, hugging bracts.

Photo 5: Flowers face upward so that purple streaking on banner, eared wings and down-turned keel are readily apparent.

Flowers of butterfly pea have an overall lavender color, the exposed portions of wings and keel with a lighter shade and the hidden clawed portions white. The stamen tube comprises white filaments tipped with light yellow anthers. The pistil, hidden within the keel, has a white style and a small knob-like, light yellow stigma. The style, with tiny hairs on the convex side, connects to an elongate, flattened, yellowish-green ovary. The calyx tube is light green.

Photo 6: Display of flower parts and a leaf. Curved style (connected to yellowish-green ovary) is to right of stamen tube with tenth stamen in between. Note adnate wings and keel petals on right and left.

With fertilization, flattened, oblong and smooth pods develop which contain up to about six seeds. Mature pods, two or more inches long with a long curved tip, split in late summer along one side and become twisted so that sticky seeds are released.

Photo 7: A mature seed pod in mid-August.

Spurred butterfly pea (Centrosema virginianum), which is found in pinelands of southern and central Arkansas, although similar and also with resupinate flowers, has several readily apparent differences: 1) twining vines, 2) smaller lavender flowers with hairy outer surface, 3) banners more circular and almost flat with white streaking only, spurred, 4) wings and keel about the same length, 5) calyx tube short with long lobes, the tube hidden by a pair of large subtending bracteoles, and 6) long skinny seed pods.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Purple, Wildflowers | Tagged Butterfly Pea, Clitoria, Clitoria mariana, Fabaceae, Know Your Natives | Leave a comment

Know Your Natives – Showy Partridge Pea

Posted on by

Showy partridge pea (Chamaecrista fasciculata var. fasciculata)* of the Pea/Bean (Fabacaceae) family is an annual forb with asymmetrical flowers. It occurs in the U.S. from New Mexico and Kansas to South Dakota and Minnesota to Maine, thence south and east to the Atlantic and Gulf Coasts. In Arkansas, it is found statewide. The genus name comes from Greek meaning “low crest”, probably referring to new leaf clusters at stem apices that are crest-like. The specific epithet is from Latin meaning “in bundles”, possibly in reference to flower clusters. Other common names include “sensitive pea” and “sleeping plant” based on folding of leaflets when touched (sometimes) and during dark, cool or rainy conditions.

Showy partridge pea grows in various soils found in prairies, open woodlands, roadsides and recently disturbed or burned areas. It may occur in dense stands in disturbed or burned areas, but plant numbers decrease as other plants become established. It has a short tap root with auxiliary roots. Plants may grow to 2 feet or more tall. In crowded situations, slender stems are erect and unbranched, but in more open areas, long ascending branches grow from leaf axils. Stems and branches, which are light green in shady areas, have reddish overtones in sunnier areas. Actively growing apices of robust stems and branches are zig-zagged and are flattened due to leaves and inflorescence being aligned on only two sides. Showy partridge pea, as do other pea species, produces root nodules in which microorganisms fix nitrogen from the air for use by the plant.

Photo 1: Shallow-rooted annual plants grow quickly. Notice crest-like leaf cluster at stem apex. Photo taken in mid-May.

Leaves of showy partridge pea, widely spaced and alternate, are aligned on two sides of stems and branches. Two long lanceolate stipules, about ¼ inch long and 1/16 inch wide, grow from base of leaves. Leaves, which have straight rachises, are about 3¾ inches long and 1¼ inches wide with ¼ inch petioles that are slightly grooved on the upper surface. Leaves are even-pinnately compound with up to a dozen or more opposite leaflets. Closely spaced, entire (smooth margins), glabrous leaflets of equal size, on tiny petiolules, are narrowly oblong, ½ inch or more long and less than ¼ inch wide. Leaflets, with rounded bases and rounded apices with a tiny apical point, are medium to dark dull green above and light green below. The closely spaced leaflets are angled toward the leaf apex and are positioned so that upper leaflets slightly overlap lower leaflets (in Venetian blind style). Pinnate venation of the leaflets can be obscure, even with magnification. Mid-veins of leaflets are off-center. A bowl-shaped nectary is located on the upper side of each petiole.

The blooming period begins in early summer. Inflorescences consist of cauline fascicles (clusters) of flowers that occur between the aligned alternate leaves. A fascicle, while still in bud-stage, has two to six buds at varying degrees of development. Buds, covered by five light green sepals, have an elongated, conical, thin-pointed shape with five prominent longitudinal bulges toward their base. Buds are borne on thin peduncles, up to ½ inch long, that have several tiny, alternate and lanceolate bracts. One flower of a fascicle blooms at a time so that flowers may be in bloom all along stems and branches. With favorable weather, blooming may continue for several months as stems and branches continue to elongate and final flowers of fascicles bloom.

Photo 2: In this mid-July photo, flowers bloom all along erect stems while stems continue to grow at the apices.

Flowers, to 1½ inches across, are showy and irregularly shaped on ½ inch pedicels that have several alternate lanceolate bracts. A five-petal, bright yellow corolla consists of 1) two upper oval petals of the same size and shape, 2) a third upper ovoid petal of similar size with a tapered base, 3) a large oval flattened lower petal and 4) another lower petal that is smaller, cupped and may be right or left of the larger lower petal. Bases of the two upper oval petals usually have a reddish splash of color while lesser basal color may be present on several other petals. Ten dark maroon stamens are tightly grouped and oriented downward to right or left into the cupped lower petal, correspondingly also to right or left. The slender stamens, with a wider lower half and skinny upper half, are of unequal length from ¼ to ½ inch. (On some plants, stamens are yellow and not as large.) A light yellow slender style with attached ovary, originating to the side (right or left) of the stamen group, extends toward the large, oval, flattened lower petal (also right or left). The curved style, 3/8 inch long with a pointed stigma, tops a ¼ inch long straight, bean-like ovary. Five lanceolate, slightly broadened, light yellow sepals become splayed behind the flower’s corolla at anthesis. Flowers fade after one day.

Photo 3: Asymmetrical flowers have five petals of four different sizes and shapes. Ten stamens twist to the right or left into a cupped petal. The style of lower flower can be seen along with overlapped leaflets, venation and immature pods.

Photo 4: Display that includes two leaves showing upper (on left) and lower (on right) sides. Note bowl-shaped nectary on petiole of leaf on left. Expanded flower separates petals from sepals, stamen group and pistil (with bean-like ovary that develops into a pod or legume, not fully mature below).

With fertilization, a flower’s ovary quickly develops into a pod. Pods, initially finely pubescent and light green, are held erect with tips upward. A mature pod, about 2½ inches long and about ¾ inch wide, may contain as many as 20 seeds, each in a squarish segment of its own. Mature pods are dry and brown, and elastically dehiscent, splitting suddenly and flinging the seeds a distance of several feet. The seeds are flat, dark brown, and vary from oval to triangular to square.

Photo 5: A developing pod can be seen at upper left. Stamen group of upper flower is oriented into the cupped petal on the right while that of the lower flower is oriented into the cupped petal on the left.

In addition to showy partridge pea, a second species of the genus occurs in Arkansas, sensitive partridge pea (Chamaecrista nictitans var. nictitans). Sensitive partridge pea, also widespread across the state, is a much shorter, more branched, and less-erect plant to one foot tall with tiny flowers. Flowers (⅛ inch long) have four petals of fairly equal size (one is cupped) with a much larger lower petal, as well as only five stamens. Leaves bear stalked nectaries. And many cauline flower “clusters” occur between leaves with only one or two flowers per “cluster”.

Photo 6: Sensitive partridge pea (Chamaecrista nictitans var. nictitans), a smaller plant, has tiny flowers and stalked, rounded nectaries (note ant at nectary of lower center leaf). Multiple flowers (see conical buds) occur between leaves.

Chamaecrista fasciculata was formerly known as Cassia fasciculata. This species is typically placed in the Pea/Bean (Fabaceae) family. However, some authorities place it in the Senna (Caesalpiniaceae) family.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Wildflowers, Yellow | Tagged Chamaecrista, Chamaecrista fasciculata var. fasciculata, Fabaceae, Know Your Natives, Showy Partridge Pea | Leave a comment

Know Your Natives – Tall bellflower

Posted on by

Tall bellflower (Campanula americana*) of the Bellflower (Campanulaceae) family is an annual or biennial forb. In the U.S., it occurs from Louisiana and Oklahoma north to South Dakota and Minnesota, east to New York, thence southward into states that border the Atlantic and Gulf Coasts. In Arkansas, it occurs across the highlands of the northwestern half of the state and along Crowley’s Ridge. The genus name is from Latin for “bell”, in reference to the “campanulate” flower shape of other species of the genus. The specific epithet relates to its occurrence in America. Preferred habitats include moist to dry loamy soils of shady to partially sunny woodland borders and openings, rocky slopes, and in drainages. Another common name is American bellflower.

Tall bellflower, reaching 3 feet or more in height, has several to a dozen stems that grow from the base of a main stem or directly from a thick caudex with light tan, smooth lateral and tap roots. A plant’s stems all have a similar height and bear flowers at the same time. Stems, terete in cross-section, are heavily hispid (short stiff hairs) in their lower portion with pubescence decreasing up-stem to become mostly glabrous in the uppermost portion of the inflorescence. Several to a half dozen axillary branches, from ½ inch to 6 inches long, may occur below a point at about ⅓ stem-length from stem apex. Stems and branches are a medium green with ridges that tie to leaf petioles. While the lower portions of stems are hollow, smaller stems and branches are filled with a white pulpy material. Plants have a milky sap. The earliest basal leaves, which have oval blades and long petioles, wilt away with stem growth.

Cauline leaves, which are alternate and have variable shape, range from to 3 to 6 inches long (including petioles) and 2 inches wide lower on stems, to tiny and needle like in the upper portion of the inflorescence along stems and branches. Shape varies from ovate-lanceolate (lower leaves) to obovate-lanceolate (mid-stem leaves) to lanceolate and linear (in inflorescence). Blades vary from having rounded bases and attenuate apices (lower leaves) to having attenuate bases and acuminate apices (mid-stem leaves) to having attenuate bases and fine pointed apices (in inflorescence). Petioles, varying from 4 inches long (lower leaves) to 1 inch long (mid-stem leaves) to sessile (in inflorescence), are hispid on their underside.

Photo 1: In this late April photo, long-petiolate cauline leaves can be seen at base of stems along with short hispid pubescence along stems and leaf margins.

Spacing of cauline leaves decreases from stem base, where spacing may be up to 2 inches, to the upper portion of the inflorescence where spacing may be ⅛ inch. Upper leaf surface is dark green with a pale green midvein while the lower surface is dark green with a silky sheen. Margins, except for smooth edged (entire) linear leaves near stem apex, are serrated with white-tipped points. Petiolate leaves have narrow decurrent wings that decrease in width down-petiole and may disappear before reaching the stem. Venation, pinnate with secondary veins arching toward the apex without reaching the leaf margin, is prominently impressed on the upper surface and expressed on the lower surface. On the upper surface of larger leaves, hispid hairs are mainly on the midvein while on the lower surface hispid hairs occur on all veins. Ciliate hairs also occur along margins of larger leaves. Leaves uppermost in the inflorescence are so tiny, needle-like, closely spaced and intermixed with flowers that they are difficult to see.

Photo 2: Display shows upper surface of cauline leaves ranging from lower leaves (see upper left) to upper leaves (see lower right). Large leaf at bottom shows lower surface of a mid-stem leaf.

Flower buds in leaf axils typically occur in groups of three (triads) in which the central bud matures before the lateral buds. Along branches, axillary flower buds typically occur singly. Triad buds, growing directly from stems/branches, do not have peduncles or pedicels. Buds are initially tightly wrapped in prominent linear sepals so that buds have a skinny conical shape. Once sepals flare backward, the actual flower bud is seen to have a round, elongate, stub-nosed shape that, as it enlarges, changes from light green to white to blue (or lavender) with a white base. As buds approach anthesis, they are deeply corrugated with pubescent, frazzled tips.

Tall bellflower has an unusual flowering sequence. Central flowers of triads about ⅓ stem-length from stem apex bloom before the two lateral flowers, with bloom sequence moving toward stem apex. As the first several central triad flowers bloom, the topmost flower of the stem does likewise. Later, blooming of the lateral triad flowers (which also moves up-stem) is joined by flowers on axillary branches. Apical flowers of branches bloom before flowers lower on the branch, if the branch has additional leaf axils. Typically, all leaf axils within the inflorescence produce buds/flowers or branches which produce buds/flowers, with extent of bloom being weather/moisture dependent.

Photo 3: The single apical bud and several lower buds (seen here still wrapped in sepals) will be the first flowers to achieve anthesis. Note smaller lateral buds of triads at lower leaf axils and smaller bud triads below apical bud.

Corollas, to about 1 inch in diameter, have five ovate to lanceolate lobes that are sky blue to lavender (may be white), typically with a distinct white center and white spots where lobes meet above the white center. Color of upper and lower corolla surfaces are the same. Straight, thin, darkened lines (veins) on both sides of the corollas extend from tips of lobes to base of the corolla tube. Lobes tend to have wavy margins and frazzled pubescent tips. Sepals reflex sharply backwards. Individual flowers remain in bloom for about two days and a plant may be in bloom for a month or more, depending on soil moisture.

Flowers are perfect (with pistils and stamens). The ovary is totally inferior, with calyx and corolla attached to its apex. The prominent purplish, smooth, strongly exserted style has a broad down-curve before trending back upward so that its three-lobed stigma is positioned directly in front of flower. When styles are first visible, they are encased in a fuzzy pinkish skin which shrinks away as pistils mature. The 5 stamens, with dilated white bases, are attached to the base of the corolla and surround the base of the style. The filaments curve upward to strap-like, twisted, light yellow anthers. With ½ inch long styles and anthers positioned much lower, the anthers are thus located well away from the stigmas, which are not receptive to pollen for another day or so (to promote cross-pollination). The conical five-ribbed, light green, inferior ovary is rimmed by a short calyx tube and five linear lobes, often with a small appendage between each pair of lobes.

Photo 4: When flowers first open, straight styles are encased with a pinkish skin (left flower) which shrinks as pistils mature and styles twist upward (see flowers from left to right). Note that stigmatic surface is not yet exposed in these three flowers. Bud shows long, reflexed calyx lobes and frazzled tips of corolla lobes.

Photo 5: Lowest central triad flowers have faded with bloom of central flowers shifting up-stem. Note corrugated buds at top of photo, three-part stigmas and broad filaments tipped with twisted anthers. Large nectar seeking bees pollinate flowers.

With fertilization, the ovary with three locules develops into a flat-topped capsule with persistent calyx lobes. Capsules are an inverted cone-shape with three ribbed sides and three flat sides. When capsules dry, stacked light tan seeds are released from round holes at the top of the three flat sides. The tiny seeds are flattened, smooth and oval.

Photo 6: With adequate moisture, flowers may continue to develop into late summer at which time seed capsules dry in unison. Dry capsules have three round holes near their top from which seeds are easily shaken. Photo in late September.

Tall bellflower, an upright annual or short-lived perennial (depending on when seeds germinate), may be welcome in a moist shady natural area or as a specimen plant in a rock garden. It has attractive foliage and beautifully shaped, typically blue buds and flowers in early summer. Bloom period extends over a month or more and, with adequate moisture, plants remain leafy into late summer. Flowers provide pollen to small bees and nectar to large bees.

Some authorities treat tall bellflower in its own different genus, Campanulastrum, due to its unusual floral characteristics and lack of bell-shaped corollas.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Blue, Know Your Natives, Native Plants, Wildflowers | Tagged Campanula, Campanula americana, Campanulaceae, Know Your Natives, Tall Bellflower | Leave a comment

Know Your Natives – Whorled Milkweed

Posted on by

Whorled Milkweed (Asclepias verticillata) in the Dogbane (Apocynaceae) family, formerly in the Milkweed (Asclepiadaceae) family, is a perennial herbaceous forb. The genus name relates to the Greek god of medicine (Asklepios, alternatively spelled Asclepius). The specific epithet is from a Latin word meaning “whorled”, in reference to the plant’s leaf arrangement. Whorled milkweed, a widely spread species, occurs from Arizona to Montana thence east to the Atlantic and Gulf coasts (but absent from Utah and Colorado as well as Maine and New Hampshire). It is found throughout much of Arkansas, except for portions of the Mississippi Alluvial Plain. Preferred habitat is sunny prairies and glades or partially sunny open woods and woodland borders, with soils sandy to limy, ranging from dry and rocky to well drained but moist.

Whorled milkweed typically occurs as solitary plants in areas not dominated by larger species. It has one to several erect, straight, slender, and terete stems that are 2 or more feet tall. Stems, light to medium green, contain white sap, as is typical of most milkweeds. Cross-sectional stem diameter decreases very gradually from ground level, where a diameter of ⅛ to ¼ inch is typical, into the inflorescence. Stems may be glabrous or puberulent (minutely pubescent) along longitudinal lines. A few secondary stems, with the same growth pattern as main stems, may grow from upper leaf whorls of more vigorous plants or after a stem has been nipped. Stems die back to the ground at the end of the growth year, but lower portions remain erect and hardened well into the following year. Plants are resistant to drought.

Whorls of leaves, which occur along the entire stem, are more widely spaced about mid-stem, with decreasing spacing toward base and apex. Space between whorls may be ½ inch in the lower portion and 1¼ inches in the mid-portion. Leaf whorls consist of three to eight very narrow, long and thin leaves with tapered tips and rounded, sessile bases. Leaves are up to 1¾ or more inches long and 1/16 inch wide with longest leaves about mid-stem, the leaf length and number decreasing into the inflorescence. Leaves of a leaf whorl are mostly in the same plane, but some whorls are slightly off-plane and an isolated leaf may occur between whorls. Leaves, mostly glabrous, are a medium to dark green above and paler beneath. Leaf bases and swollen nodes are also a lighter green. The base of a leaf is ascending with the remainder of the leaf trending horizontally or slightly descending. Margins are entire and tightly rolled downward (revolute) so that a leaf feels thicker than it really is. Other than a slightly recessed midvein above, leaf venation is obscure. Like the stems, the leaves contain a white sap. Lower leaves drop off with dry soil conditions.

Photo 1: Leaves in a whorl may not necessarily all lie in a single plane (they may be staggered slightly). Note puberulent longitudinal lines along stem.

Inflorescences consists of a few to a dozen umbels along the upper portion of the main and secondary stems. Umbels have up to about twenty flowers each. All leaf whorls within the inflorescence zone tend to produce one to several umbels. Umbels may have an overall light green color or, in sunnier sites, have a reddish shading, especially evident on petals. Peduncles, growing from stems at a sharper angle than adjoining leaves (ascending at about 45 degrees), are straight and up to 1½ inches long. Pedicels, also straight, have a length of up to ¾ inch. Blooming sequence of the umbels progresses from lowermost to uppermost, the bloom period extending often over a month or more in larger plants. An umbel in bloom may be up to 1½ inches across, depending on the number of flowers. Small, narrowly linear bracts occur at the base of the umbels, fading as the umbels mature. Peduncles and pedicels are terete and may be puberulent.

Inflorescence becomes evident in late spring after stems have attained most of their eventual height. When they first appear, the umbels comprise tight clusters of round-topped buds, each shaped by five corolla lobes already free of their very small calyxes. Buds may be a light green or, in sunnier sites, reddish brown.

Photo 2: In this mid-May photo, these lower umbels are mostly in bud, with a few flowers at anthesis. Note reddish coloration, linear bracts at base of umbels and lighter green lower mid-vein of leaves on the left.

Photo 3: Umbels of this 30-inch-tall, two-stemmed plant vary from being in full bloom to those in early development (as seen at top edge of photo).

With anthesis, small flowers on straight, slender, ⅓-inch pedicels are about ¼ inch long. Each corolla is composed of a short tube bearing five cupped, sharply reflexed, linear-ovoid lobes of the same coloration as the flower was in bud. The corona is composed of five elevated white hoods (nectar chambers) with prominent, protruding, inward-pointing white horns. Staminal filaments are fused into a tube called the column, while the anthers and stigmas are fused into a unique, head-like structure, the gynostegium. Flowers are set in a deeply divided calyx of five lanceolate lobes that are 1/4 the length of the corolla. Other than possible reddish coloration on the corolla lobes, flowers are whitish to light green.

Details regarding the complex pollination process of milkweeds may be found in an article about red-ring milkweed.

Photo 4: Details of the flowers’ coloration (from a sunny site): corolla lobes and coronal hoods and horns can be seen.

Ovaries of some of the fertilized flowers develop into erect or ascending, smooth, long, narrow and pointed pods that are from 3 to 4 inches long and ½ inch wide. When pods (follicles) are mature and dry, they split along a longitudinal seam to expose a number of flat, ovate, brown seeds pressed together at the base of the pod. Seeds have many white, silky, filament-like hairs attached at their apices which fill the remainder of the pod. As the pod splits, winds pull seeds out by tugging on the long hairs and wing-tissue along the edge of the seeds.

Photo 5: In fall, pods approach maturity and plants provide a food source for monarch caterpillars. Revolute leaf margins are evident on the brown leaf at lower left.

Photo 6: Mature seeds with apical hairs are dispersed from pods by the wind. Two young monarch caterpillars can be seen.

Whorled milkweed, in comparison with most other native milkweeds, has a small stature that does not attract immediate attention in a garden or woodland setting. However, it is an important plant for insects (including monarch caterpillars) that is fairly easy to establish from seed and does not become invasive. It is not favored by deer and is resistant to drought.

Fourteen species of milkweed in the genus Asclepias occur in Arkansas. With its narrow, linear and mostly whorled leaves, whorled milkweed is easily distinguished from the other milkweeds, with perhaps the exception of narrow-leaf milkweed (Asclepias stenophylla) which is known from only a couple of north-border counties. Narrow-leaf milkweed also has narrow, linear leaves and whitish flowers; however, its leaves are alternate to nearly opposite and its greenish flower umbels are nearly sessile.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, White, Wildflowers | Tagged Asclepias, Asclepias verticillata, Know Your Natives, Milkweed, Whorled Milkweed | 1 Comment

Know Your Natives – Self-Heal

Posted on by

Self-heal (Prunella vulgaris ssp. lanceolata*) of the Mint (Lamiaceae) family is a perennial herb found in generally moist soils. It occurs as a native species throughout the lower 48 states and Alaska. In Arkansas, it occurs throughout the state. The origin of the genus name is not known. The specific epithet is from Latin for “common” as in “widespread”. The subspecies name is from Latin, meaning “lance-like”, a reference to the leaf shape. Other common names include lance-leaf self-heal and heal-all. Self-heal grows well in various moist soils with full or partial sun in prairies, woodland borders and roadsides. It was widely used by Native Americans and early settlers for medicinal purposes and it is still used as a medicinal herb.

Photo 1: A mature plant prior to stem development. Leaf blades, marked with glandular dots, have slight serrations on their margins.

Self-heal has shallow, light tan, long fibrous roots that radiate from a small central caudex, and the plant may also produce short roots from the lowermost portion of the stems that are in contact with soil. Plants may have one to a half-dozen mostly erect stems with a final height from 6 to 12 inches or more. Secondary stems may grow from upper leaf axils of main stems. Stems are square in cross-section (a characteristic of mints) with sharp corners. Width of stems, at about 1/16 inch, is fairly uniform from stem base to uppermost leaves. Stems are a light green, but the lower portion may be reddish.

Photo 2: In mid-May, this plant in a sunny site has 20 stems with minimal secondary stem growth.

Basal and stem (cauline) leaves have a similar appearance although basal leaves tend to have longer petioles in relation to leaf blade and may have more prominent glandular dots. Cauline leaves, opposite and widely spaced, are petiolate except for the uppermost leaf pair, which have variably shaped “petioles” (see below). Blades, broadest below mid-leaf, are broadly lanceolate to ovate with an obtuse tip and rounded to cuneate base.

Leaves of self-heal, medium green in color, may be 2 inches long and ¾ inch wide, or larger. Margins may be entire (smooth) or have widely spaced hardly noticeable serrations and may be undulating. Venation, recessed above and prominent below, is pinnate with a half-dozen or so secondary veins that are offset across the primary vein (midvein). These secondary veins, extending from the primary vein, stop short of the leaf margin and fade out as they arch toward the leaf apex. The recessed appearance of the primary vein continues down the petiole as a central groove. Petioles may have thin wings that extend down from the leaf blade, with the wings more evident nearer the blade.

The uppermost pair of cauline leaves generally occurs immediately below the inflorescence, but a short stem segment may occur between the uppermost leaf pair and the inflorescence. In the case of secondary stems, the uppermost pair of leaves are typically the only leaves on the stem, but occasionally another pair of leaves may be present. Appearance of the uppermost leaf pair varies from plant to plant regarding shape of blade and petiole. The blade outline may be similar to other cauline leaves or more linear and may be on a very short petiole or sessile. Alternatively, the “petiole” may be thin and widened so that its appearance is similar to that of the floral bracts (see below), with the blade size reduced and strongly linear.

The inflorescence is a rounded, cylindrical cluster at the tip of the stem, typically immediately above the final leaf pair. Clusters have a loose, spongy feel. Clusters, at the time of flowering, are about 1 inch long, but may be 2 inches long when flowering is completed. Flowering occurs in late spring and lasts for about a month. Flowers may bloom sequentially in tiers from lowermost to uppermost or flowers at anthesis may be scattered throughout the cluster.

Inflorescence clusters are composed of leafy floral bracts and flowers that are attached to a columnar peduncle. Floral bracts occur in opposite pairs. Like the leaves, each pair is rotated 90 degrees from the pairs directly above and below it (decussate). These cordate (heart-shaped) bracts may be up to ½ inch long and wide; they are sessile, ciliate (hairs on margins), tissue-thin, and light green with a darker green or purple rim. Bract size decreases from the inflorescence base to the apex. A whorl of six flowers occurs immediately above the floral bracts with fewer than six flowers per whorl near the top of the cluster. Above the final whorl, several pairs of decreasingly-sized bracts create a flattened top. When floral bracts have especially long pointed apices, the typically round cluster appears square.

Photo 3: Display showing upper and lower leaf surfaces along with a stem terminating with a flower cluster. Leaves, stems and calyxes are pubescent.

Photo 4: Display of an expanded cluster alongside its stalk and axis. Cluster had five whorls of flowers, each whorl sited above a pair of floral bracts. Numbers with bracts correspond to numbers along stripped axis to show point of origin.

The tubular corollas are first seen as dark-colored nubs that appear from within calyxes. A flower, about ¾ inch long from base of calyx to end of corolla, has an upper lobe and three smaller lower lobes. Pedicels are very short. The exterior of the upper lobe is typically purple (as first shown by nubs), while the lower lobes and the interior of the flower are a lighter color. The four lobes join within the calyx to form a constricted floral tube. The upper lobe, with a notched central ciliated ridge, is hump-backed above the notch toward the end of the lobe so that a hood (galea) is formed. Rounded margins of upper lobes are flared upward. Two oblong lateral lower lobes are projected forward while the larger middle lower lobe, with a broad fringed margin, bends down.

Flowers have four stamens (forked at top) that are adnate (fused) to the floral tube and a bifurcated style attached at the depression in the center of the deeply 4-lobed ovary. The four stamens are forked near the tip, with a longer pair and a shorter pair, together with the stigma, positioned under the hood of the upper lip of the corolla.

The calyx, comprising an upper and lower lobe of different structure and shape, is open and gaping before corolla nubs appear. The upper lobe is hump-backed with a flattened upper side and two lateral rounded sides. The lower lobe, more narrow and planar, is positioned between the sides of the upper lobe. While the top of the upper lobe is mostly featureless, the sides of the upper lobe and the lower lobe have longitudinal ridges. The ridges on the lower lobe terminate as two pointed teeth. The upper lobe has a rounded to truncated, notched (emarginate) apex with three tiny spines.

Photo 5: Ciliated ridge of hump-backed upper corolla lobes and fringe on middle lower lobe can be seen. Top of cluster is closed by floral bracts.

Photo 6: Pairs of rounded floral bracts separate whorls of flowers set in spiky calyxes. Lowermost bract is indicated by an arrow.

Self-heal is typically pubescent. Stems are densely covered with stiff hairs (hispid) which continue along petioles and, to a lesser degree, onto leaf blades. The lower leaf surface is more pubescent than the upper surface, especially along veins. Sides of the upper calyx lobe are hispid while the dorsal surface is glabrous. The lower calyx lobe is also hispid.

A fertilized ovary produces a brown cluster of four tiny, smooth, brown and egg-shaped nutlets that are retained in an upright position into late summer. As rain drops strike the fruiting clusters, nutlets can be flipped out of the calyxes for dispersal by flowing water.

Photo 7: In this early July photo, fruiting clusters have dried and stems are deteriorating.

Self-heal is a “pleasant-looking” small perennial that may work well in a moist sunny garden. It has attractive leaves, flowers and flower clusters–good plant for bees and butterflies. This native mint does not seem to spread aggressively by seed although it does spread by rhizomes. If reseeding is an issue, bloomed-out flower clusters can be easily removed. Flower clusters may be eaten by deer which would encourage an extended bloom period via lateral branching. Being herbaceous (non-woody), the above-ground portion of this perennial plant disappears in winter.

The non-native self-heal (Prunella vulgaris ssp. vulgaris) is reported from scattered areas across the U.S., but is not currently known to occur in Arkansas. Whereas stems of Prunella vulgaris ssp. lanceolata are mostly erect and with mid-stem leaves that are three times as long as wide, stems of Prunella vulgaris ssp. vulgaris, a shorter species, generally recline on the ground, with roots at leaf nodes and mid-stem leaves twice as long as wide.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Purple, Wildflowers | Tagged Know Your Natives, Lamiaceae, Prunella, Prunella vulgaris, Self Heal | Leave a comment

Know Your Natives – New Jersey Tea

Posted on by

New Jersey tea (Ceanothus americanus) of the Buckthorn (Rhamnaceae) Family is a small, deciduous, thorn-free shrub. The genus name originates from a Greek word for “spiny plant” or a Latin word for “thistle”. The specific epithet relates to its occurrence in the Americas. In the U.S., it is found from Texas to Nebraska to Minnesota thence east and south to the coasts. In Arkansas, the shrub occurs statewide. Another common name is wild snowball. Habitat preference is variable, but the species is typically found in dry to well-drained soils of sandy, sunny prairies or rocky slopes and open woodlands. Leaves were used as a tea substitute during the American Revolution.

Photo 1: In mid-May, this young plant exhibits rapid apical stem growth that will not produce inflorescences in the current year.

New Jersey tea, maturing with a dense rounded shape at 2 to 3 feet tall, has erect to ascending stems and branches. Plant height is limited because apical buds of mature plants do not develop and upper portions of stems and branches die over winter. In spring, multiple new branches grow from the previous year’s leaf axil buds on surviving portions of stems and branches. Also, new stems may arise from near ground level, which produce inflorescences the first year. Current year’s stems and branches, slender and pubescent with short fine hairs, become rigid and woody during the year.

Photo 2: Also in mid-May, this mature plant approaches maximum bloom.

Current year’s stems and branches are light yellowish-green, with similar color retained on those that survive for a second year, although slightly darker and without pubescence. Older surviving stems and branches become trunk-like and brown and roughened. Stems, branches and trunks are round (terete). With a stout, deep taproot and excellent regrowth abilities, New Jersey tea is resistant to drought, fire and deer. In conjunction with bacteria, New Jersey tea “fixes” nitrogen in the soil much like many legumes.

Buds occur at all leaf axils of current year’s stems and branches. The uppermost two to eight axillary buds produce floral branches (see below) in the current year while lower axillary buds remain dormant to produce branches with inflorescences the next year.

Alternate leaves are irregularly spaced from about ½ to 2 inches along current year’s stems and branches. Leaf size, too, is irregular, but generally, the largest leaves are in the mid-section of stems and branches. Largest leaves are about 2¼ inches long and 1 inch wide with ¼ inch petioles that may be slightly reddish. Leaves are elliptic, with a rounded base and broadly acute tip, and they appear slightly rough. Upper and lower leaf surfaces have short pubescence so that leaves, when carefully handled, feel like flannel. Upper leaf surface is a medium green while lower surface is more yellowish-green and dull, with prominent pale yellow veins. Veins are slightly recessed above and expressed below. Uniformly sized and shaped serrate margins extend from the lower one-fourth of the leaf blade to the apex.

Leaves have unusual and distinctive venation. Three primary veins originate at the petiole, with the two arcuate (curved) laterals terminating at the leaf margin about a fifth of the leaf-length from the apex. All secondary veins are arcuate.

Inflorescences occur as multiple elongate globular clusters of tiny flowers at the ends of floral branches that grow from upper leaf axils of current year’s stems. The floral branches, which may be 2½ inches long and tend to be twisty, are leafless or occasionally bear one or two small (to ¼ inch long) leaves. Floral branches and peduncles have the same color and pubescence as current year’s stems and branches.

Flower clusters, which may be 1 inch or more long and ½ inch or more in diameter, consist of many tiny white flowers in small panicles around a central axis. Within the panicles, multiple flowers grow from common points. Clusters, which may be held upright or oriented in various directions, can have 200 flowers. Flowers in each cluster bloom at about the same time, with the clusters originating from lower on the stem or branch blooming first. Flowers are slightly fragrant.

Photo 3: Display of a flowering branch separated into sections. Note unusual leaf venation and long twisty, leafless peduncles. Lower side of a leaf is shown at left-center.

Flower buds nearing anthesis have five rounded-triangular sepals that tightly cover five enclosed petals that cover five large anthers (one anther per stamen). Buds, when viewed from above, are star-shaped with five rounded “knobs” created by the enclosed anthers. With anthesis, sepals separate slightly, but remain in the same position as in the bud. The five fragile-looking petals, with broad cupped apices and long narrow bases (ladle shape), extend through the opening between sepals and flare wide. The large yellow pollen-bearing anthers are at first within the bowl of the ladle, but later, anthers become dark (pollen having been discharged) and filaments project anthers above the corolla. Flowers, 3/16-inch-wide from petal tip to petal tip, are positioned in a flat plane well above slender white pedicels that are as long as the flowers are wide.

Photo 4: Flower buds are knobby due to size of enclosed anthers. Several flowers are shown at anthesis such as the one at lower-center. Note long white pedicels.

Photo 5: Inset of a single flower shows pollen-bearing anthers shifting out of bowl of ladle. Several more mature flowers within the panicle, also shown, have dark pollen-free exserted anthers.

Flowers, with fertilization, produce triangular, 3-chambered, rough, light-green capsules about ¼ inch wide on green stems (previously white pedicels). Capsules become black at maturity and the upper portion splits to release a single smooth, brown, ovoid seed from each chamber.

Photo 6: In this mid-July photo, some of the triangular seed capsules have matured (black ones) and split to release seeds. Previously white pedicels are now green.

A second species in the genus occurs in Arkansas; namely, “inland New Jersey tea”, also called “redroot”, (Ceanothus herbaceus), which is known from a number of western and central counties. Although also a woody shrub, it was given the epithet “herbaceus” when it was described because it was mistakenly thought to be an herbaceous perennial. This species has narrower, glabrous leaves that are tapered at both ends. Smaller and more rounded or dome-shaped flower clusters occur terminally from the uppermost leaf axil of each stem. Inland New Jersey tea generally blooms a few weeks earlier than New Jersey tea.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Shrubs, White, Wildflowers | Tagged Ceanothus, Ceanothus americanus, Know Your Natives, New Jersey Tea, Rhamnaceae | Leave a comment

Know Your Natives – Western Daisy

Posted on by

Western Daisy (Astranthium ciliatum) (formerly Astranthium integrifolium*), of the Aster (Asteraceae) family, is an annual species with daisy-like flower heads. In the U.S., it is found in Arkansas, Oklahoma, Texas, southern Nebraska and southwestern Missouri with greatest concentrations in eastern Oklahoma and western Arkansas. The genus Astranthium comprises about a dozen species from the southern U.S. and Mexico, with only a single species in Arkansas, reported from the Ozarks, the Arkansas River Valley and the Ouachitas. Another common name is Comanche western daisy. The genus name is from the Greek for “star” referring to the star-like flower heads as seen from above. The specific epithet, also of Greek origin, means “fringed with hairs” in reference to the plant’s pubescence. Western daisy is found primarily in full or partial sun in sandy, clay or loam soils of grasslands, glades, and open deciduous woods mostly in lowlands. Plants have short, tough tap roots or multiple, radiating, near-surface roots up to 2 inches long.

Western daisy is a small plant that germinates in the fall into winter to form a flat-lying rosette of basal leaves, up to several inches across. Basal leaves, which have entire (smooth) margins, have an oval shape with a gradually narrowed base (spatulate) and long hairs on the upper surface. In late winter, ascending leaves, attached to a rudimentary main stem, appear from the center of the basal leaves as the basal leaves begin to fade.

Photo 1: In mid-March, new leaves appear as the winter leaves fade. Note pubescence.

Stems, which are light green, are slender, with three to four slight ridges that connect with petiole-stem junctions. Faint reddish shading may be present on stems, especially on ridges. The single main stem typically has secondary stems that arise from lower leaf axils at about 35 degrees off the main stem.

In less desirable sites (excessive shading, crowding, etc), plants may remain small with no or few secondary stems. In more desirable sites, secondary stems become dominant and, in turn, may bear stems that arise from their upper leaf axils. Secondary stems, which are fairly straight, are erect on smaller plants and spreading to ascending on larger plants. Stems are covered by soft hairs.

Photo 2: In less desirable sites, plants remain small with limited secondary stem growth. White flowers shown with the western daisies are of long-flower cornsalad (Valerianella longiflora).

Alternate stem (cauline) leaves have the same light green color on upper and lower sides as the stems; however, lower sides are slightly shinny. Blades of lower cauline leaves, to 1¼ inch long and ½ inch wide, have an elongate oval shape that is entire and widest at mid-blade, becoming gradually more narrow toward their sessile bases (oblanceolate). Blades of upper cauline leaves become increasingly smaller and more narrow up-stem, with more pointed apices (lanceolate) and while remaining sessile. Lowermost leaves have relatively long pubescence on upper blade surfaces and margins (ciliate) and have glabrous lower surfaces. Spacing of cauline leaves varies with the greatest spacing being at the lowermost portions of stems where spacing may be up to 1¾ inches while other leaves may be spaced at ¼ inch. Leaf-stem junctions are at about 35 degrees from which point lower leaves recurve downward while upper leaves extend mostly outward.

The primary inflorescence of western daisy, at apices of stems, consists of single composite flower heads on long peduncles. Peduncles, measured from the base of the flower head to the uppermost cauline leaf, vary from short (1 inch or less) to long (to 3 inches). Peduncles have the same appearance as stems. As peduncles grow and strengthen, flower head buds are at first upright, then droop and then become upright again at anthesis. A plant’s first flower head to reach anthesis, regardless of plant size, is that single head at the apex of the main stem.

Photo 3: In more desirable sites, as shown by this single plant, secondary stems become dominant. Flower head at apex of main stem can be seen mostly hidden at center of plant. Note drooping flower head buds.

Photo 4: Display of flower heads from buds (lower left) to past-anthesis (lower center).

Flower heads, up to about an inch wide, have up to about 20 pistillate ray florets and numerous bisexual disk florets (radiate flower heads). Flower heads have a slightly domed center and rounded (hemispheric) involucres. Strap-like ligules of the ray florets, about ¼ inch long, have rounded to notched apices and constricted bases. Ligules typically overlap, but may also be spaced slightly apart. The constricted bases of the ligules are not especially visible except when ligules are spaced apart. Ligules are typically light lavender, but may be white. Lavender ligules may or may not have white coloration near their bases, with the color change being gradual or sharp. Tiny disk florets, yellow with yellow pollen, have five triangular spreading lobes on the rim of a short corolla tube set on a green ovary. Exserted anthers, cohering into a short tube, make pollen available to insects when the style, like a plunger, pushes through their tube, depositing the pollen on the surface of the disk. Involucres, composed of about 20 thin, lanceolate, green, equal-length and appressed phyllaries, are slightly overlapped along their translucent edges.

Photo 5: Disk florets have five lobes on their corollas and anthers fused into a tube, as shown by the outer ring of florets. Ligules have constricted bases and rounded to notched apices. The disks of composite heads typically flower from the outside in toward the center. Here the head is just getting started. Notice how immature the central disk floret buds are compared to those near the perimeter.

Photo 6: Involucre composed of lanceolate, slightly overlapping phyllaries. Peduncle, slightly ridged and pubescent, has same appearance as stems. Spiders and pollinating insects often have encounters on flower heads.

With fertilization, each floret produces a single one-seeded achene of two fused carpels (the two halves of a typical sunflower seed wall), surmounted by a ring of hairs at the top (pappus). With fruit (achene) dispersal, a conic, pitted receptacle remains.

Western daisy (Astranthium ciliatum) has been assigned to various species and subspecies over time. The most recent reassessment defines western daisy (Astranthium ciliatum) as being found west of the Mississippi River and eastern daisy (Astranthium integrifolium) as being found east of the Mississippi River.

Footnote: There are several other species of composites in Arkansas, representing various genera, that may also have “daisy” in their common names.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Purple, White, Wildflowers | Tagged Asteraceae, Astranthium, Astranthium ciliatum, Know Your Natives | Leave a comment