Know Your Natives – Aniseroot

Aniseroot (Osmorhiza longistylis) of the Carrot (Apiaceae) family is a herbaceous erect perennial that has pleasantly aromatic roots. It occurs across most of the U.S. from New Mexico to Montana, thence east to the Gulf and Atlantic Coasts, with the exception of Louisiana and Florida. In Arkansas, the species occurs in the Highlands of the northwestern half of the state and on Crowley’s Ridge. The genus name is from Greek words for “aromatic root”. The specific epithet is from Latin for “long-styled”. Other common names include sweet anise, long-style sweet-cicely, and smooth sweet-cicely*. It occurs in moist deciduous woodlands with light to moderate shade in soils enriched with decaying plant material.

Plants have thick, branching tap roots that terminate in long fibrous roots. Crushed roots have an anise scent.

In spring, new buds sprouting from the caudex (stem base) develop into basal leaves and a compressed mass of developing stems, leaves and inflorescences. Fully developed basal and cauline leaves have three pinnate leaflets that may be further pinnately divided into sub-leaflets (ternately pinnate to bipinnate). At the end of the growing season, stems decay while basal leaves may become ground-hugging and persist into spring.

Photo 1: In this early January photo of branching taproots, previous year’s basal leaves persist (extending off top of photo) and buds for new growth can be seen on caudex.
Photo 2: In this early April photo, a mass of developing stems, leaves and inflorescences emerge at center of plant. The large basal leaves are bipinnately compound, as are cauline leaves that will develop later.

Above the basal leaves, mature plants have one or two erect, typically pilose (densely short-pubescent), solid stems that grow to a height of about 2½ feet. Nodes are rather swollen and bear single cauline leaves which may subtend lateral or floral branches. Stems are a light green with lower portions and areas near nodes sometimes purplish. 

Photo 3: Immature ternately bipinnate leaf has a clasping base from which a compound umbel (with white flowers) has grown along with a lateral branch that bears another developing umbel (hanging down). Photo – April 15.

The compound leaves, to about 9 inches long and 12 inches wide, are divided into three principal sections (ternately compound). Leaflets have thin, rather flimsy blades with prominent irregularly wavy (sinuate) margins. They are a dull light to medium green on both surfaces. Stalks of leaves and leaflets are rounded on their upper side and flattened and grooved beneath. Crushed leaves have a light anise scent. 

Photo 4: This plant has two ascending basal leaves and two well-developed, cauline leaves, of which the uppermost subtends a peduncle with white flowers in a compound umbel. Note fine pubescence along purplish stem.

Inflorescences, flowering in mid-spring, are terminal and axillary compound umbels, consisting of one or two slender peduncles about 2 inches long. These terminate in three to six rays, each tipped by 5 to 17 pedicels supporting the umbellets of flowers. Rays are subtended by an involucre of 1-6 bracts, the umbellets by an involucel of 4-6 bractlets. Umbellets bear about 5-17 flowers, of which 5-7 are perfect (having both pistils and stamens), typically arranged around the perimeter of the umbellet, and the rest staminate. Flowers bloom in quick sequence from the outside toward center of umbellets so that fruiting begins while staminate flowers remain at anthesis.

The perfect flowers have no sepals, five white petals, five stamens, and a pistil of two united carpels with two free styles. As flowers open, stamens are curved inward before becoming erect. Stamens and knob-like anthers are initially white, but anthers become light tan as pollen develops. Styles have an enlarged base, the stylopodium, a characteristic of most species in the carrot family. The inferior ovary bears white hairs along longitudinal ribs, similar to the ciliate hairs of the floral bracts. The open corolla is ⅛ inch wide; the ovary at its tip, just below the corolla, is about 1/16 inch wide.

Staminate flowers, about 1/16 inch wide, have more slender pedicels and small bowl-shaped receptacles. Petals and stamens of staminate flowers are similar to those of the perfect flowers, however, the petals remain crimped together–the corolla does not flare outward.

Photo 5: This compound umbel has four umbellets of which the lower three have perfect and staminate flowers while the upper umbellet has staminate flowers only. Stigmas are held well above corollas. Note ciliate pubescence of bracts and bractlets and the ribbed ovaries.

Ovaries that are fertilized mature into long (to 1 inch) slender dry fruits called schizocarps that split into two 1-seeded halves called mericarps. These are slightly flattened and have longitudinal ribs with stiff forward-appressed hairs. Styles are persistent on the mericarps as spiny projections. At maturity, mericarps separate from each other and from the central axis so that only their tips cling to the tip of the central axis. At full maturity, black mericarps are slightly curved with a long spiny proximal tip and a short spiny distal tip (the persistent style). As various animals or birds brush against plants, the spiny tips and side-hairs become entangled in fur and feathers, providing seed dispersal.

Photo 6: In mid-June, schizocarps have split into two mericarps that cling to tips of the central axes. Upper leaf section shows adaxial surface while lower leaf section shows abaxial surface. Dried remnant is the third leaf section. (Parts separated for photo.)

For a native plant garden or natural area with moist soil and partial shade, this non-showy perennial may add extra texture and help in-fill an area. This perennial member of the carrot family does not seem to self-seed agressively. Roots, flowers and leaves are edible in salads or as a garnish.

Fifty-five species of the Carrot family occur in Arkansas, of which a number have bipinnate leaves and compound umbels. Characteristics of aniseroot that aid in its identification include: 1) a perennial species, 2) branched tap roots that have an anise scent, 3) broad leaves with bluntly toothed leaflets, 4) short dense pubescence along stems, 5) umbellets with perfect and staminate flowers, 6) petals of perfect flowers that have clawed tips, and 7) linear fruits. Aniseroot can be separated from the only other Arkansas species in the genus, hairy sweet cicely (Osmorhiza claytonii), by aniseroot’s 1) shorter, less conspicuous pubescence, 2) styles that extend outside corollas, 3) fruits that have prominent spiny hairs on longitudinal ribs, and 4) a stronger anise scent.

*  The word “anise” relates to a non-native culinary species (Pimpinella anisum) which has roots and leaves that also have an anise scent. “Long-style” compares aniseroot’s style to the shorter style of hairy sweet-cicely (Osmorhiza claytonii). The word “cicely” probably originates from European sweet-cicely (Myrrhis odorata). Aniseroot is also called “smooth sweet-cicely” based on its lesser degree of pubescence, as compared to hairy sweet-cicely.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Mayapple

Mayapple (Podophyllum peltatum) of the Barberry (Berberidaceae) family is an herbaceous perennial that has one or two large leaves per stalk. The genus name is from Greek words for “foot” and “leaf”, in reference to the appearance of  the leaves. The specific epithet, from Latin, is a reference to the vegetative leaf’s umbrella-like form, in which the petiole joins the leaf blade on its lower surface rather than the margin. In the U.S., mayapple, the only North American species of Podophyllum, occurs from Texas to Minnesota eastward to the Atlantic and Gulf Coasts. In Arkansas, mayapple occurs statewide. (A second species of Podophyllum occurs in east Asia.) Habitat consists of shady to partially sunny, mixed deciduous forest and forest edges with dry to mesic soils, along with moist open areas. Plants are also called American mandrake based on the superficial similarity to the unrelated European mandrake, Mandragora officianarum.

Mayapple develops an extensive shallow layer of reddish brown, rope-like rhizomes, to ¼ inch in diameter, that elongate annually by adding 2- to 8-inch-long straight segments. The ends of the segments have numerous down-turning fleshy white roots. Rhizomes do not have any noticeable growth nodes. With several new rhizomes branching from the ends of previous years’ segments, open to dense colonies may form with hundreds of leaves.

In late winter, vegetative growth develops from the terminal buds on previous years’ rhizome segments. The first growth to appear is a white “cone” formed by several imbricated protective bracts. As one to two large leaves develop, the cone spreads open. At first, leaf blades are down-drooped around hidden stalks so that the flat white centers of the leaves are the first leaf-portion to appear out of the cones. In the case of two-leaf stalks, two white centers appear, separated by an ovoid flower bud. Stalk growth quickly frees the growing furled leaf blades from their protective cone and they open umbrella-like.

Photo 1: This 3-inch tall, two-leaf stalk has furled leaves separated by a flower bud. Basal protective bracts quickly fade as stalks grow. Note marginal ciliate pubescence. Photo – March 16.
Photo 2: Terminal buds of previous year’s rhizome segments produce new stalks (extending off top of this photo). Basal protective bracts have become tissue-thin. White nubs will become new rhizome segments. Fleshy roots are concentrated below stalks. Photo – April 5.

Stalks, 1½ to 1¾ feet tall and ¼ inch in diameter, are erect, terete and glabrous. Stalks that support two leaves are forked at about two-thirds their height so that stem-length above the fork is 3 to 6 inches. Stalks bearing one or two leaves are of similar height and have the same light green to reddish coloration. Stalks are totally smooth. At the end of the growing season, stalks quickly disintegrate, leaving a round scar on the persistent rhizome.

Leaves, to 14 inches across, have an orbicular outline with up to nine shallowly to deeply incised lobes, depending on leaf size. Lobes are obovate in outline and separated by deep clefts. Leaves are a medium green above, often mottled, and a lighter green below. The upper leaf surface is glabrous, the lower surface and margins densely short-pubescent. Venation is strongly recessed above–creating a smoothly wrinkled surface–and strongly expressed below, with main veins dividing distally and terminating at the apiculate tips of the lobes. 

Photo 3: This colony may be a single plant (a clonal colony) or a number of intertwined plants. Photo – March 30.

Leaf shape of one-leaf stalks, with center of leaf blade attaching to stalk, is peltate. Leaves of two-leaf stalks have fewer lobes, the “missing” lobes directly above the fork in the stalk, so that leaf shape becomes off-set palmate (point of stalk attachment not fully centered) to palmate (point of attachment at leaf margin). One leaf of two-leaf stalks tends to be smaller than the other.

The mayapple inflorescence comprises a single flower positioned in the fork of two-leaf stalks. When stalks first emerge, flower buds are positioned slightly above and between the emerging leaf pair. With stalk and leaf growth, buds become hidden well below the large leaves. Buds, on slender sturdy pedicels to 1½ inches long, have three light greenish bowl-shaped sepals that drop off as the corolla swells. With anthesis, the large (to 3 inches wide) white flowers face downward. (Several rare forms of mayapple are known to occur.*)

Photo 4: Inflorescence consists of a single flower in the fork between the two leaves. Red buckeye (Aesculus pavia var. pavia) in background. Photo – April 4.

Flowers have five to nine petals, 12 to 15 stamens, and a single superior ovary. The white, waxy, obovate petals are 1½ inches long and wide. Stamens have ¼-inch-long pale yellow filaments and ¼-inch-long light yellow anthers that release pollen as they dehisce (split) along their lateral margins. The light green ovary is tipped by a prominent, pale yellow, crinkled stigma atop a short, stout style. Flowers are fragrant. Ovules are massed on a single broad placenta along one side of a central cavity.

Photo 5: Buds (bottom of photo) have three light-green sepals that drop off as flowers open. Flowers have five to nine overlapping petals, 12 to 15 stamens, and a large ovary (hidden in photo by crinkled stigma).
Photo 6: This half-inch-long ovary was dissected just after anthesis. Ovules are attached to a single placenta on the ovary wall.

A fertilized flower produces a berry that ripens in mid-summer. Mature fruit, about 1½ inches long, becomes pale yellow as leaves and stalk wilt and dry. Fruits drop to the ground where they become accessible to various small mammals as well as box turtles (Terrapene carolina), resulting in seed dispersal. The smooth seeds resemble apple seeds.

Photo 7: Leaves (at top of photo) have dried, while fruit remains green. Fruits have a flattened side. Prominent stigma is persistent. Photo – June 13.

Mayapple’s conspicuous foliage and colonizing tendencies may be welcome in a woodland garden or natural area where it would add a dramatic flair. The easily viewed parts of flowers and fruit can make it an educational tool. Gardeners can easily establish new colonies by transplanting rhizome segments as foliage declines. All above-ground evidence of plants disappears from summer until spring. Ripe fruit, with seed removed, is considered to be edible while all other portions of the plant (including unripe fruit) are known to be toxic. Mayapple contains podophyllotoxin, which is used in developing prescription drugs and for cancer research. Foliage is not eaten by deer or rabbits.

* Podophyllum peltatum forma deamii has pink-tinged flowers and maroon fruit. Podophyllum peltatum forma polycarpum produces a cluster of fruit. Podophyllum peltatum forma biltmoreanum produces orange fruit.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Southern Corydalis

Southern corydalis (Corydalis micrantha subsp. australis)* of the Poppy (Papaveraceae) family, formerly of the Fumitory (Fumariaceae) family, is an over-wintering annual that reproduces both sexually (chasmogamous flowers, which are cross-pollinated) and asexually (cleistogamous flowers, which are self-pollinated). In the U.S., it occurs from Texas and Louisiana, north to Kansas and Illinois, and then east along the Coastal Plain from Mississippi to North Carolina. In Arkansas, the subspecies is scattered throughout the Interior Highlands and West Gulf Coastal Plain. The genus name is the ancient Greek name of the crested lark, referring to the spur of the flowers. The specific epithet, also from Greek, means “small flower.”  The subspecific epithet is Latin for “southern.” Habitats vary from wooded floodplains, to open woodlands, to waste areas, roadsides and other disturbed areas, frequently in sandy soils.


Southern corydalis is a low-growing plant with a short taproot that terminates with many thin long fibrous roots. The plant germinates by winter and dies by early summer. The widely spreading, ascending to reclining, slender stems are square in cross-section with widely scattered alternate leaves that grow from the corners of the stem. When not confined by other plants, its multiple stems (to 11 inches long) radiate in all directions. Early growth tends to be bluish (glaucous) while a mature plant typically has light dull green leaves. Stems and petioles tend to be reddish. The glabrous (hairless) plants regenerate by seed only. Fruiting capsules of chasmogamous and cleistogamous flowers have the same appearance.

Plants in late winter have a cluster of basal leaves. With stem growth, compound cauline leaves and axillary leaves become distinguishable. Petioles (leaf stalks) of cauline leaves have a clasping base, a rounded lower surface with a central ridge (a continuation of the stem corner) and a flattened to channeled upper surface. Petioles of axillary leaves are non-clasping and square. Cauline leaves have up to seven leaflets, axillary leaves typically five, arranged sub-alternately along the leaf rachis. Leaflets, ½ to 1 inch long, are deeply incised so that each leaflet has a terminal lobe and a pair of lateral lobes. Incisions of the leaflets result in margins that are crenulated and divided into rounded to short finger-like segments, with obtuse often mucronate apexes. As shown by the photos below, the leaves are lovely and delicate. The largest may be 3½ inches long and 1 inch wide.

Photo 1: New leaves are glaucous while older leaves of this annual plant have reddened in response to cold temperatures. Photo – February 21.

Photo 2: This plant with cleistogamous flowers at the time of photo has actively growing stems with long compound leaves. A single first-fruit can be seen at far-left. Photo – March 11.

 

Photo 3: This full-length stem has four axillary stems. The three lower axillary stems to the right have cleistogamous inflorescences, while the terminal raceme is chasmogamous.

Flowering occurs from mid-March into late April. Primary and secondary stems bear both terminal and lateral racemes. To 3 inches long, chasmogamous racemes have up to a dozen flowers with each flower subtended by an acute obovate sessile bract. The persistent bracts, to ⅛ inch long at flowering and ¼ inch at fruiting, have entire margins.  Cleistogamous racemes are often fewer-flowered.

Chasmogamous flowers are bright yellow, four-petaled and up to ⅝ inch long and ½ inch high (side view) and ¼ inch wide (front or bee’s eye view). Upper and lower petals have rounded faces and a central sharply depressed area expressed abaxially as a sharp keel. In side view, the upper petal extends sharply backwards, paralleling the lower petal, before rising slightly to form an inflated, round-tipped nectar-spur. The nectar-spur extends about ¼ inch beyond the pedicel (flower stalk). The flower’s corolla is slightly longer from the pedicel forward than backward to the tip of the nectar-spur.

Flowers also have a matched pair of lateral petals that are pressed together at the flower’s center to form what appears to be a rounded up-flared single petal. The combined lateral petals envelop a short style (atop an elongate ovary) and stamens that tightly surround the ovary. The two-lobed stigma is barely exposed at the flower center. The lateral petals are about ¼ inch long.

Photo 4: Main photo shows a raceme with chasmogamous flowers and fruit, each subtended by a bract. Lower inset: front of a flower, upper petal to left. Upper inset: stamens, ovary and stigma exposed.

Cleistogamous flowers bear very different petals. Upper and lower petals are significantly smaller than those of chasmogamous flowers, do not flare outward, and lack a nectar-spur. Diminutive lateral petals envelope anthers and stigma so that self-pollination occurs.

Photo 5: Display of a chasmogamous raceme (lower) and a cleistogamous raceme (upper), both with fruit capsules. A cleistogamous flower, with upper and lower petals removed, is positioned above. Squares are ¼ inch.

As flowering extends upward in the raceme, the ovaries quickly develop into bean-like, erect capsules as the raceme elongates to 6 inches or more. The 3/4-inch long or slightly longer capsules, beaked by a persistent style, from chasmogamous and cleistogamous flowers, have the same appearance. Each capsule comprises two valves enclosing a single locule or cell. Each of two placentas on the inner walls of the capsule, extending from base to apex, bear a single row of alternating seeds. While still green, capsules dehisce along two sutures to release about 15 shiny, black, dimpled, flattened-ovoid seeds, each measuring less than 1/16-inch across. The seeds carry a small, fleshy, clear-gloppy structure at their base called an elaiosome. Elaiosomes are ant food: seeds are transported to the ants’ nest where elaiosomes are eaten and the seeds themselves discarded–a remarkable but not uncommon dispersal mechanism. 

Photo 6: Fruits dehisce to disperse shiny seeds that bear gloppy elaiosomes (ant food). In this photo, one of two placentas can be seen at open-center of capsule (within shadow). Squares are ¼ inch.

Three other species or subspecies of the genus are found in Arkansas. Mealy corydalis (Corydalis crystallina) has ovaries and fruit that are covered in a gray or white mealiness. Mealy corydalis is usually found in prairies, often concentrated on prairie mounds.  Pale or yellow corydalis (Corydalis flavula) has smaller, usually paler yellow flowers and fruit that hang downward on long pedicels. Pale corydalis is usually found in riparian forests or other moist forests and woodlands.  Small-flower corydalis (Corydalis micrantha subsp. micrantha) has shorter, fewer-flowered, chasmogamous inflorescences that are not held well above the leaves, as well as shorter and stouter fruits (under 6/10 inch long).  Small-flower corydalis is apparently very uncommon in the state and is reported to grow on bluffs and rocky hills, on glade margins, and in riparian forests.

* Some recognize this plant at the species level, as Corydalis halei.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Crested Iris

Crested iris or dwarf crested iris (Iris cristata) of the Iris (Iridaceae) family is a low-growing iris that produces light blue flowers in early spring. In the U.S., it occurs from Oklahoma, Arkansas and Missouri east to Atlantic Coastal states. In Arkansas, the species occurs across the Ozark Plateaus, Arkansas Valley and Ouachita Mountains. The genus name is for Iris, the Greek goddess who personifies the rainbow. The specific epithet, from the Latin meaning ‘crested,’ refers to the flower’s distinctive crests (see below). Preferred habitat is well-drained, mesic, sandy to rocky, fertile soils in partially sunny woodlands.

Roots of crested iris emerge from thick, horizontal, underground stems called rhizomes that grow just beneath or at the surface of the soil.  Crested iris rhizomes alternate between thin and swollen sections. The prominent segments of these underground stems are modified nodes, tightly covered by persistent brown, scarious (papery) bracts, which are themselves modified leaves. The base of each bract inscribes a growth ring around the rhizome. Bracts mostly hide the light yellow epidermis of the rhizome; the solid tough rhizome interior is also light yellow. All vegetative growth, both above and below ground, originates from the rhizomes. A rhizome may produce several to as many as eight aerial stem growth points (apically and laterally) along with several new rhizome growth points (apically, after culmination of vegetative growth) that form new underground branches. Rhizomes do not produce new growth after the second year, but they persist so that thick mats may develop.

Photo 1: Display of an especially healthy underground clump showing brown rhizomes with fibrous roots and green, aerial growth. Photo–late March.

Aerial growth occurs as either vegetative stems or flowering stems. Both stem types have a short (less than 1 inch), slender central stem that bears flat, dagger-shaped, alternate leaves. Smaller leaves, lowermost on a stem, are imbricate and tightly encircle the round stem, while distal leaf growth forms an elongate fan with the leaves flattened in a single plane. The closely spaced node pattern of the rhizomes continues on the stems. 

Photo 2: With aerial growth, leafy vegetative stems and reproductive flowering stems become distinguishable. In this photo, three flowering stems are shown in the foreground, two to left and one to right. Photo–late March.

All leaves above the duff layer are a yellowish to medium green and glabrous (those in duff being whitish). Leaves have a broad base transitioning to a broader mid-leaf that gently tapers to the tip. Leaves, with parallel venation and smooth margins, are mostly straight, but apically may curve toward or away from the central hidden stem. Leaves are about 6 inches long and ½ inch wide.

Leaf size on a vegetative stem gradually increases distally, with a few significantly smaller leaves at the base and six to eight larger leaves above. Leaves have a tight pocket, an adaxial slit (toward the stem) in the lower portion that partially extends into the blade. As new leaves grow, one above another, each is initially sheathed by the previous leaf. The uppermost pair of leaves on flowering stems (1 to 2 inches long) forms an enlarged, sharply keeled pocket that protects developing flowers and fruits.

Photo 3: Leaves overall have a flattened, dagger shape, with new leaves initially sheathed by older leaves. Uppermost leaves of flowering stems have leaf pockets that sheath the flower bud and fruit. Photo–early April.

The terminal inflorescence consists of one or two flowers, with those of a colony tending to bloom in unison. Flowers are large and showy, 2 inches in diameter, typically an overall pale blue to lavender, but occasionally white. They have three sepals (falls), three petals (standards), and three style-arms. Hidden underneath each style arm is a stamen. The three showy components, in a radial pattern, are arranged in layers, the sepals lowermost, petals next, and style-arms uppermost. The petals alternate with the sepals and style-arms–the style-arms, and the hidden stamens, lie directly above the sepals. Sepals are united at their base to form a slender tube, to three inches long, that extends to the ‘inferior’ ovary hidden deep within the pocket formed by the two uppermost leaves of the reproductive stem. Sepals are 1¼ to 1½ inches long and petals are somewhat shorter. Style-arms are about 1 inch long.

 

Photo 4: Two reproductive or flowering stems and a vegetative stem. Note the sheathing of leaves by lower leaves and the opposing pair of ‘pocket-leaves’ that subtend flowers and hide the ovary. The long flower ‘throat’ is the tube down which pollen tubes grow to reach the ovules in the ovary. The ovules become the seeds.

Widely spreading sepals are obovate (narrow at base and broad above mid-section) with a broad marginal band of the overall flower color that surrounds a narrow purple band. From mid-sepal downward, the ‘signal-patch’ (the area of contrasting color) has three ridge-like crests (the basis for common and scientific names) that extend toward the flower’s throat. The golden yellow central ridge is vertically rippled (when seen from above) while rippled parallel ridges on either side are yellow on their inward side and white outside. The area between the three ridges is yellow with purple markings. The ridged area of the sepal is strengthened (to support large bees) while the remainder of the sepal’s surface is flimsy.

The widely spreading petals and style-arms are of uniform color. Petals are narrowly obovate to oblanceolate with the rounded apical portion and undulating lateral margins. Style-arms are oblong with a slightly tapered base and a rounded, up-turned fringed apex that has a deep v-notch.

Photo 5: Flowers of this plant are almost white. Sepals with colorful signal-patches are overshadowed by the shorter style-arms. Petals are positioned between and above the sepals.

A single large stamen is located directly below each style-arm, with the elongate anther pressed against the roof of the style-arm. The pollen-receptive stigma is slightly exerted from the tip of the style-arm’s abaxial surface. The grooved, triangular ovary, ¼ inch long, is hidden at the base of the long floral tube.

Photo 6: Sepals to left and petals to right. Style-arms remain in position; note long white anther directly below arm. Stigma is contained by style-arm. Note ovary’s position at base of style tube, an adjoining flower bud hidden by leafy bracts, and nodes along stem.

With fertilization, ovaries develop into capsules that remain hidden within the leafy pockets. Half-inch long capsules have a pointed-oval outline in side view and a triangular cross-section. Capsules dehisce within the leafy pockets. Small, dark-brown, roughened, oval seeds are less than ⅛ inch long. Seeds have a sticky appendage (viscid aril) that wraps over their top so that seeds may attach to birds and animals.

Crested iris, being a short plant with intertwined rhizomes, is a choice plant for a woodland garden or natural area, if it remains uncluttered by other vegetation. Partially sunny areas with various well-drained mesic soils are ideal. This blue-flowering plant survives temporarily dry soils, is not eaten by deer, and does not readily self-seed. It can be a delightful, low-maintenance, six-inch-tall ground cover.

Crested iris is one of eight species of the genus Iris that occur in Arkansas. Of the other seven, only the rare dwarf iris (Iris verna var. smalliana) is low growing. Dwarf iris, a species of conservation concern, typically has dark blue flowers with a golden signal-patch without crests and with rhizomes of a uniform narrow width.

Other irises in the state:

  • Zigzag or short-stem-iris (Iris brevicaulis)
  • Blackberry-lily (Iris domestica, formerly Belamcanda chinensis) – not native
  • Copper or red iris (Iris fulva)
  • Garden iris (Iris germanica) – not native
  • Yellow iris or yellow flag (Iris pseudacorus) – not native and invasive
  • Southern blue flag (Iris virginica)

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Hairy Skullcap

Hairy skullcap (Scutellaria elliptica) of the Mint (Lamiaceae) family is one of nine skullcap species known to occur in Arkansas. The genus name is from the Latin scutella, a dish, in reference to the distinctive shape of the lower portion of the fruiting calyx (see below). The specific epithet refers to the leaf shape. The common name “skullcap” refers again to the unique form of the calyx, in particular the upper portion. This herbaceous perennial occurs in well-drained, sandy to rocky soils in partially sunny deciduous woodlands, woodland edges, and stream banks and terraces.  In Arkansas, it is only known to occur in the Interior Highlands.

Hairy skullcap, with a large number of slender, light tan, ropy roots, has a mature height of about 1 to 2 feet. New stems in late winter tend to be purple, but that color fades to a medium green with time. The plant, without runners or rhizomes, has up to a half-dozen erect square stems, with secondary, axillary stems arising along their upper portions. Main and axillary stems have terminal inflorescences. Axillary stems, in matched opposite pairs, are typically leafless except for leaves subtending the inflorescence. Stems are covered with dense short fine pubescence (tomentose), so that young stems appear fuzzy. As is true for all skullcaps, plants do not have a minty scent. Stems, although not woody, may persist over winter. Opposite leaf pairs are widely separated and decussate (adjoining pairs rotate 90 degrees).

Photo 1: Roots bear current-year and previous-year stems along with a bud for the next year. Inset: a tomentose stem and a pair of leaves (upper surface to left, lower to right).

Leaves below the inflorescence are up to 3 inches long and 1¾ inches wide, triangular-ovate, with scalloped margins (crenate). Leaf bases may be nearly straight (truncate) to rounded or slightly wedge-shaped (cuneate), with narrow strips of blade extending part way down the  petioles. Leaves, attached along the flat faces of the square stems, are a dark green above and a yellowish green beneath. Petioles, about ½ inch long, are rounded below and flattened to channeled above. In comparison with pubescence of the stems, that of the leaf blades is sparse, although longer and denser hairs occur along the primary and secondary vein below. Leaf margins are ciliate with short hairs.

Higher up the main stem, leaves that subtend axillary stems or flowers become gradually reduced, more elliptical, and with margins less crenate to entire. Also, petioles shorten and decurrent blade material may extend to the stem.

Photo 2: Opposite leaves are widely spaced on erect stems. A dead stem from the previous year remains at center-right. Photo – early April.
Photo 3: Upper leaves of the main stems subtend axillary stems or individual flowers. Leaf size and spacing decreases above. Photo – mid-May.

In mid to late spring, spike-like terminal racemes up to 4 inches long bloom over several weeks. Lower in the inflorescence, individual flowers are subtended by a leaf whereas higher flowers are subtended by small bracts (see below). Flowers, becoming more closely spaced up the raceme, are positioned in opposite decussate pairs. Sturdy, ⅛-inch-long pedicels, with two tiny basal bracts, extend out from the rachis at 45 degrees. Stems and rachises within the inflorescence have tomentose pubescence, becoming glandular on pedicels and calyxes.

Photo 4: Adaxial (left) and abaxial (right) surfaces of a leaf pair along with two racemes. Up-rachis, leaves become more elongate and less scalloped.

Flowers of all skullcaps have an oddly shaped calyx that becomes distinctively dish-shaped as fruits develop and the dorsal “skullcap” enlarges to become the prominent upper portion (see Photo 6 with both flowering and fruiting calyxes). With anthesis, a fist-shaped, closed corolla pushes out of the calyx, so that the skullcap is pushed backwards. The corolla’s tubular base bends sharply upward as the “fist” expands and opens. After the corolla drops off, the calyx again closes.

Corollas of hairy skullcap, about ¾ inch long, are elaborately bilabiate (two-lipped), with light blue to violet shades that fade into white accents. Lighter colors (often white) occur along the center of the lower lip and across the winged lobes of the upper lip. The upper lip is three-lobed: an upper lobe constricts to form a projecting, nearly-closed hood and two lateral lobes that “wing” outward. The lower lip has a broad, rather convex, notched central lobe and two down-flared lateral lobes. Flowers have two frontal orifices: the small upper orifice of the hood and the lower larger orifice formed by the two lips.

Flowers have four slender stamens and a slender style that are mostly hidden within the corolla tube and upper lip. Stamens, with their filaments fused to the lower portion of the corolla tube, occur as two pairs. The slender white filaments, with long hairs, bear two-lobed pubescent anthers that are positioned just inside the small orifice of the hood. The filaments surround a white style which extends from the four-lobed ovary to the opening of the hood. The small tapered stigma is slightly exserted. (When large bees land on the lower lip to collect nectar, the anthers are positioned to deposit pollen on the back of the bee or the stigma to collect pollen from the back of the bee.)

Photo 5: Base of tubular flowers bends sharply upward to an out-facing corolla. Anthers are hidden within the closed hood and stigma is slightly exserted from the hood.
Photo 6: Small bracts subtend flowers in upper portion of raceme. Flowers bloom sequentially from base to apex. Photo – mid-June.

Following anthesis, corollas quickly drop off. With fertilization, one to four ovules–one in each lobe of the four-lobed ovary–form seeds as the calyx enlarges to about ¼ inch. The fruit is a round, dark, one-seeded nutlet with numerous tiny wart-like tubercles across its surface. The calyx dries to a light tan color and the “skullcap” drops off so that nutlets may be dislodged by wind and rain. The “dish” section of the calyx remains on the dry plant into winter.

Photo 7: Display (a square = ¼ inch) showing the lower calyx section (on left – the dish section), the upper calyx section (on right – the skullcap section), and the tuberculate nutlets. (As shown, in reference to dish section, skullcap section is upside-down and reversed.) Photo – early September.

Hairy skullcap is appropriate for a partially shady garden or natural area with moist soils. This small- to medium-sized erect perennial herb has attractive foliage and beautiful, intriguing blue flowers. It does not have runners or rhizomes so that “extra” plants from self-seeding may be easily removed. Plants may be eaten by deer.

Nine species of skullcaps (one with three varieties) occur in Arkansas. They all have blue to violet flowers, but leaf shape can generally be used to distinguish hairy skullcap from the other eight species. A species with similar leaves is heart-leaf skullcap (Scutellaria ovata), but its leaf margins are more serrate and its adaxial leaf surface has a coarser appearance.

Species and varieties of skullcaps that occur in Arkansas:

  • Bush’s Skullcap (Scutellaria bushii)
  • Gulf Skullcap (Scutellaria cardiophylla)
  • Hairy Skullcap (Scutellaria elliptica)
  • Hoary Skullcap (Scutellaria incana)
  • Rough Skullcap (Scutellaria integrifolia)
  • Mad-Dog Skullcap (Scutellaria lateriflora)
  • Heart-Leaf Skullcap (Scutellaria ovata)
  • Southern Skullcap (Scutellaria parvula var. australis)
  • Glade Skullcap (Scutellaria parvula var. missouriensis)
  • Small Skullcap (Scutellaria parvula var. parvula)
  • South American Skullcap (Scutellaria racemosa) (non-native)

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Ernest’s Spidewort

Ernest’s spiderwort (Tradescantia ernestiana) of the Commelinaceae (Spiderwort) family is an early-blooming, low-growing species, one of the 12 spiderworts that occur in Arkansas. The genus name honors John Tradescant, gardener to Charles I of England, while the specific epithet honors American botanist Ernest Jesse Palmer. This spiderwort occurs in Missouri, Oklahoma, Arkansas, Mississippi and Alabama. In Arkansas, the primary areas of occurrence are the northwestern portion of the Ozark Plateau, the Ouachita Mountains, and higher elevations of the Arkansas Valley. It is also known as woodland spiderwort. The name “spiderwort” has been ascribed to various origins.*

Ernest’s spiderwort occurs in moist sandy to rocky soils in shady to partially shady sites found along wooded slopes, bluffs, woodland edges and lowlands, as well as along drainages and open wet fields. This herbaceous perennial has a multitude of light tan, slender, fleshy roots that radiate outward at shallow depth. Leaves, emerging in mid-winter, are produced in separate basally sheaved, tightly-held clusters, each originating from a separate growth point on a broad, irregular caudex. New clusters develop alongside older clusters and from new growth points around or under the caudex. In favorable sites, dense expanding clumps may form. On any particular plant, a few or many clusters produce a central floral stem.

Photo 1: Some clusters of leaves may produce a floral stem. Inset, showing parts of same plant as in main photo, has arrows indicating developing new clusters. (Leaves damaged by cold temperatures.)

A cluster may have basal leaves only (non-blooming plants) or basal leaves transitioning to cauline (stem) leaves. Leaves higher on stem are spirally arranged and well spaced. Cauline leaves have basal sheaths, tightly wrapped around the stem, with the length of sheath decreasing toward a terminal inflorescence. Largest leaves, at mid-stem, may be to 11 inches long and 1½ inches wide. Leaves are arching and strap-like (broadly linear to lanceolate) and attenuate (gently tapering) to an acute apex. The long, arching and overlapping leaves, in-folded along the upper midrib, give the overall leaf mass an angular appearance. Leaf margins are straight to undulating and entire (uncut). While early leaves are highlighted with reddish shades, later leaves are a lustrous to dull medium green. Leaves are not glaucous (no white coating) and may be glabrous (no pubescence) to puberulent (short soft hairs). Venation is parallel and extends onto sheaths.

Photo 2: First leaves, appearing in mid-winter, may be reddish. Photo – mid March.

Mature plants produce main stems that may have a few secondary stems from the axils of upper cauline leaves. Stems are ascending to arching, glabrous to sparsely pubescent. All parts of the plant are somewhat succulent. With drying soils and warming conditions, plants go dormant by mid-summer; however, with improved conditions, plants may produce new growth. All above-ground evidence of plants disappears soon after they go dormant.

The inflorescences, with blooms from mid to late March into April, are in the form of umbels at the apexes of terminal and secondary stems. Umbels consist of flowers on slender pedicels about an inch or more long, situated between subtending pairs of sessile, leaf-like bracts at the tops of the stems. Pedicels may be glabrous or have short pilose pubescence (thin weak hairs). Length of stems is such that flowers remain within the leaf mass.

When buds first appear, they are pressed together in several stacks. Flowers reach anthesis sequentially, from uppermost to lowermost, initiating bloom when the stem first emerges. With only a few flowers of an umbel in bloom at one time, blooming may continue for a week or two. Buds and flowers are ascending, but after anthesis the spent flowers become nodding to drooping. Flowers open in early morning for a half-day (longer on cooler days).

Photo 3: A clasping, alternate cauline leaf can be seen on left stem along with opposite sessile bracts that subtend the inflorescence. Note tightly stacked buds on right stem. Photo – early April.

Flowers of separate plants range from light to dark pink, blue and purple (rarely white), with the color being shared by petals, filaments, wispy filament hairs, and style. Flowers, to 1½ inches in diameter, have three triangular, light green, boat-shaped sepals. When in bud, sepals are positioned margin-to-margin, forming a tear-drop-shaped calyx. At anthesis, the flower’s three sepals (½ inch long, ¼ inch wide) and three petals spread wide with tips of sepals positioned between petals. Petals are broadly ovate to almost orbicular and very showy. Upper petal margins are variously flexed and may be slightly irregular. Flowers have six ascending stamens with bright yellow anthers and exquisitely beautiful, wispy filament hairs, each hair consisting of single cells visibly connected end-to-end. The colored style, broader than the filaments, bears a white, terminal stigma. The plump ovary is three-chambered. With the passing of anthesis, the calyx again becomes tear-drop shaped and persists into fruiting. The exterior of the sepals is covered with dense, long, pilose pubescence.

Photo 4: Flowers may be light to dark pink, blue or purple. Note the six stamens (with wispy hairs and lobed anthers), single style atop a triangular ovary, and tips of sepals between the petals.
Photo 5: Calyxes, on growing pedicels, are positioned upright in bud and flower, but droop after anthesis. Plant to right is rose vervain (Glandularia canadensis).

With fertilization, three-chambered capsules form that have central placentation. The oval capsules dehisce (split) at their top and sides, spreading wide with the three sections positioned between the sepals. A capsule may produce a half dozen or so flattened, round gray seeds.

For a partially shaded to shady natural area that has moist to wet soils, Ernest’s spiderwort may be a desirable plant. Its mid-winter attractive growth provides early evidence of spring and its early flowers are a highlight of the season. Flower color of various plants varies from light to dark pinks, blues and purples. In more favorable sites, even a large plant remains a non-aggressive self-seeder. Plants disappear in summer, but may have re-growth when conditions improve.

Photo 6: Ernest’s spiderwort can form clumps. In comparison to some other taller spiderwort species, flowers mostly remain within the leaf mass.

Spiderwort species (Tradescantia spp.) are notoriously difficult to tell apart. In Arkansas, five common and seven uncommon spiderworts have been recorded. Characteristics of Ernest’s spiderwort that may help distinguish it from other spiderworts include 1) preference for shady sites, 2) early inflorescence, 3) darker flower colors, 4) wider leaves, 5) shorter clumping habit, and 6) pilose pubescence mostly on sepals and pedicels.

In Arkansas, similar species in similar habitats, easily confused with Ernest’s spiderwort, are the uncommon Ozark spiderwort (Tradescantia ozarkana) and the uncommon Virginia spiderwort (Tradescantia virginiana). Flowers of Ozark spiderwort are lighter colored (usually white) and have smaller sepals. In Arkansas, its range overlaps with Ernest’s spiderwort, and the two are known to hybridize. Virginia spiderwort typically has blue flowers and narrower leaves. It is at present only found in eastern Arkansas, outside of the range of Ernest’s spiderwort.

*   The term “spiderwort” has several possible origins: 1) leaf arrangement that looks like a “squatting” spider, 2) webby hairs on filaments, and 3) sap of stem can be drawn out into a webby string.

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Know Your Natives – Carolina Larkspur

Carolina larkspur (Delphinium carolinianum subsp. carolinianum) of the Buttercup (Ranunculaceae) family has irregular (bilaterally symmetrical) springtime flowers that are typically deep blue. The genus name is based on a Greek word for “dolphin”, in reference to the shape of flower buds (when viewed from the side). The specific epithet is a reference to one of the Carolinas, presumably the site of the type collection, i.e., the collected specimen upon which the species is based. In the U.S., the species Carolina larkspur occurs from New Mexico to North Dakota, east to Wisconsin, Kentucky, and South Carolina, and south to the Gulf Coast. The typic subspecies discussed here occurs from northeastern Texas and Louisiana, north to Iowa and Illinois, and across the Southeastern states. In Arkansas, it occurs throughout much of the state except for low lying areas of the Mississippi Alluvial Plain and West Gulf Coastal Plain. Habitat preference is sunny to partially sunny, dry-mesic to dry sandy or rocky woodlands, glades, prairies and roadsides on various substrates. The species is also known as blue larkspur and wild larkspur.

Carolina larkspur is an herbaceous perennial. It has a ground-hugging rosette of basal leaves in mid-winter, flowers in early spring, and mature fruit in late spring, after which the plant becomes dormant. 

The plant has basal and stem (cauline) leaves that, in outline, have an overall round to triangular shape. Leaf blades are deeply, palmately cut into three primary lobes, a terminal lobe and two laterals, and may be 3+ inches long and wide. Leaves are medium green adaxially, with lighter colored primary veins, and a lighter yellowish green abaxially. Blade and petiole are finely short pubescent to glabrate. Petioles, slender with a widened base, are round in cross-section with a flattened adaxial side . Venation is recessed above and expressed below, with the lower midvein being channeled.

Lobes of the earliest basal leaves have a wedge-shaped base and a fan-like apex. As additional basal leaves grow, their lateral lobes become deeply incised (though not reaching the petiole) so that leaves appear to have five primary lobes. With subsequent new leaves, lobes become more subdivided and sinuses more incised, till ultimately the blades comprise narrow, finger-like lobes, resulting in a “skeletal” appearance. Regardless of the degree of subdivision, lobing retains a pattern-of-three. Basal leaves wither, in age sequence, as the inflorescence develops.

Photo 1: Trifoliate character of leaves is readily seen in older basal leaves. Degree of leaf incision increases with later leaves. Photo – late January.
Photo 2: Structure of basal leaves become increasingly complex; however, trifoliate character of leaf blade and lobes is maintained. Photo – early March.

Stem leaves are widely spaced from stem base to immediately below the inflorescence, where they are replaced with bracts (see below). Leaves are arranged alternately, with lower stem leaves similar to the upper basal leaves. Leaves at the stem base have slender petioles to 6+ inches long; petioles are shorter about mid-stem and absent (leaves sessile) just below the inflorescence. Up-stem, both the size of the leaf blades and the complexity of their lobing decrease. Leaf coloration and venation are the same as that of basal leaves.

Photo 3: As the floral stem develops, the earliest wider-lobed basal leaves have withered. Remaining leaves have a “skeletal” appearance. Lowermost stem-leaves have especially long petioles with widened bases. Photo – late March.

Main stems, to about four feet tall, are erect, straight, terete and, typically, have downy pubescence (puberulent). (A shorter larkspur species that has similar basal leaves and blue flowers is dwarf larkspur, Delphinium tricorne.) Main stems support a raceme that may be a foot or more long. More robust plants may have shorter secondary stems growing from leaf axils at about 45 degrees that support shorter secondary racemes. Flowering proceeds from base to apex with fruits (capsules) already maturing at base as upper flowers continue to bloom. Flowers are each directly subtended by a pair of small opposite, linear bracts.

Photo 4: This robust plant is developing secondary stems at leaf axils along upper portion of main stem. Leaf size and degree of lobing decrease up-stem. Blooms of a much shorter dwarf larkspur can be seen in background. Photo – mid April.
Photo 5: A natural stand of Carolina larkspur in a sunny, rocky glade. Stem at left-foreground bears seed capsules, as upper flowers continue to bloom. Photo – Mid May.

Larkspurs are among the showiest of our native wildflowers. Close examination reveals that it is the petaloid sepals, rather than the petals themselves, that create the main attraction. Flowers, measuring about 1½ inches long and an inch wide, are typically a deep blue, but may be purplish or white. The symmetry is bilateral, described technically as irregular or zygomorphic, with one sepal of the dominant calyx positioned above the flower center and two sepals to either side. From the front of the flower (bee’s eye view), all sepals look the same, broad with a rounded apex and a distinct indentation on the face that corresponds with a green protrusion on the back. However, when viewed from the side, a half-inch-long, up-curved elongate, conical spur extends from the back of the upper sepal. 

Flowers also have four irregular petals that are significantly smaller than the sepals and are generally the same color, but petals may have various markings and color shadings. A matched pair of upper petals is very dissimilar to a matched pair of lower petals. While the sepals are thin in texture, the petals are thickened. The upper petals have an exserted up-flaring triangular portion with larger semi-tubular spurs that extend backward and are enclosed within the spur of the upper sepal.  This complex, compound tube serves as the nectary.

Lower petals, trending downward, are distally broad, rounded, and v-notched. Their outer surface bears long white twisty hairs, especially centered along the notches.

Stamens, pistils and ovaries are hidden below the lower pair of petals, although anthers may be partially visible. Three elongate, stubby whitish ovaries, fused to one another, directly above the pedicel, are in close contact with a number of stamens. Ovaries have stubby tapered styles tipped with the stigmas. Stamens have white flattened twisty filaments and dark elongate anthers.

Photo 6: Five sepals dominate the flowers’ appearance. Four irregular petals are grouped at center. Reproductive parts of flowers are mostly hidden by the two lower petals. Photo – late April.
Photo 7: A larkspur flower exploded to show parts (not Carolina larkspur). #1 – pedicel with pair of bracts. #2 – lower pairs of sepals. #3 – Upper sepal with partial spur; arrows indicate points of attachment. #4 – Upper pair of petals;  arrows indicate point of attachment (note semi-tubular shape with closed distal end). #5 – lower pair of petals. #6 – stamens. #7 – pistils (two of three shown).

The fruit of a fertilized flower comprises three slender, erect, dull-green follicles that are ½ to 1  inch long and fused together below to form a kind of three-parted capsule. The base of the capsule has a raised ring (calyx scar). Follicles are beaked with remnants of their  styles. When dry, the tannish papery follicles split, each along an inward suture at the upper end. Seeds drop free through the opened sutures or when follicles disintegrate. Tannish seeds have roughened, rounded and flattened surfaces.

Carolina larkspurs do well in rocky, sunny sites where soils are well drained. In a garden setting or natural area, mid-winter basal growth provides early greenery. Later stems provide early height to a garden, and blue flowers add dramatic impact, either singly or in groups. Larkspurs are attractive to various bees, including bumblebees, which often take the nectar by piercing the spur. An infestation of aphids can wipe out the inflorescence. Delphiniums are known to be toxic to humans and mammals. 

Two other subspecies of Carolina larkspur grow in Arkansas, both uncommon in the state: pinewoods larkspur (D. carolinianum subsp. vimineum) and plains larkspur (D. carolinianum subsp. virescens). Both are known in Arkansas only from the southwestern portion of the state. In comparison to Carolina larkspur, pinewoods larkspur has fewer, larger leaves with longer petioles and each with three primary, wider divisions. It occurs in sandy soils and is restricted to the Coastal Plain, ranging primarily in south-central and eastern Texas and western Louisiana. Plains larkspur also has fewer leaves with longer petioles, and white to light blue flowers.  It grows throughout the Great Plains, especially in prairies.  Both retain their basal leaves while the plants are in bloom, in comparison to the typic subspecies.

In addition to dwarf larkspur (D. tricorne, noted above), two other species are found in the state, namely, Moore’s delphinium (D. newtonianum) and Trelease’s larkspur (D. treleasei), both of very limited distribution in north (and west-central = Moore’s) Arkansas. Moore’s delphinium grows in moister, shaded sites and has less divided stem leaves and more diffuse inflorescences that bloom from apexes to the bases.  Trelease’s larkspur has flowers on long pedicels and grows exclusively in dolomite (a calcareous type) glades in the central Ozarks Highlands.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Red Buckeye

Red buckeye (Aesculus pavia var. pavia*) of the recently expanded Soapberry (Sapindaceae) family–it now includes the maples from the former Aceraceae as well as the buckeyes and horse-chestnuts previously classified in the Hippocastanaceae–has large, showy red inflorescences in early spring. The genus name, a classical name for an oak tree, is based on the Latin for “edible acorn”; however, red buckeye’s nut-like seeds are poisonous. The specific epithet honors Petrus Pavius, a 16th-century Dutch botanist. In the U.S., this species occurs principally from south-central Texas to southern Illinois, east to the Atlantic and Gulf Coasts. In Arkansas, it occurs statewide except for portions of the western Ozark Highlands and low lying areas along the Mississippi River. Red buckeye’s preferred habitat is the understory or margin of mixed woodlands, on lower slopes, in valleys and along stream banks, in full to mostly partial sun, where deep mesic soils are well drained. Other common names include scarlet buckeye and woolly buckeye. “Buckeye” refers to the appearance of the seed.

Red buckeye may be a shrub or small tree with a height of 20 feet or more (term “tree” used herein). Plants can produce flowers and fruits by their third year when they may be only a foot tall. Mature trees produce a dependable fruit load. Seeds dropped to the ground germinate readily, if they remain moist. Seedlings quickly develop a tap root and leaves.

Mature trees tend to be broad with a rounded top, especially in sunnier sites. Stout new branch segments (herein, term “branch” includes “twigs”) with scattered round lenticels (pores) are typically reddish at first, but become green over the growing season and then greenish gray to gray in subsequent years. Older branches are smooth and round with the small lenticels becoming raised. Younger trunks, with brown and gray splotches, are mostly smooth to slightly fissured and still marked with lenticels. Older trunks have fissured bark with flat blocky plates.

Overwintering apical buds may occur singly (when branch was not terminated by an inflorescence the previous year) or as an opposite bud pair (when branch was terminated with an inflorescence the previous year). Apical buds at the tree’s perimeter are typically reproductive, comprising both embryonic leaves and an inflorescence, and are impressively large. Buds have an outside layer of brown, tightly imbricated scales which, in late winter, spread open as underlying scales grow into strap-like, drooping, pinkish bracts. Scales and bracts quickly fall away as the branch matures.

Red buckeye’s structure is open, with denser branching on sunnier sites. Each year’s new growth produces mostly straight stout segments from a fraction of an inch to a foot long. New spring branch segments have downy hairs (puberulent), which is lost over the growing season. The greatest growth rate occurs on branches that terminate across the crown and, even more so, around the tree’s mid-section. Expansion of the mid-section is due to the dominance of the lower of the two opposite terminal buds, so that near-horizontal branches develop. Heavy fruit loads at the branch tips further enhance this spreading, shrub-like habit. Branches that grow from less dominant buds do not die; they just grow more slowly. When a vertically positioned branch terminates with a pair of opposite buds, two divergent branches develop. Young branches have prominent shield-shaped leaf scars that fade away the second year.

Photo 1: Older trunks become fissured with blocky plates. Inset photo shows a seed (the “buckeye”) and a terminal branch segment: beyond the opposite buds (the lower is dominant) is a dead peduncle (stalk of inflorescence), one branch of which still bears the remains of the fruit wall from which one or more seeds have fallen.  Photo – mid-March.
Photo 2: When branches regularly produce terminal inflorescences and the lower bud of the remaining terminal bud pair dominates year-to-year, near-horizontal branching develops. Photo – Jan 20.

Red buckeye has opposite, palmately compound leaves with five or seven leaflets joining at apex of the petiole (leaf stalk). Leaves are widely spaced along the branch (to 2 inches or more apart) and can grow to be quite large (to about 14 inches wide and long) on long slender petioles (to about 6 inches). Leaflets, broadly lanceolate, on ¼-inch petiolules (leaflet stalks), often droop from the petiole apex. They have a shiny medium green adaxial surface with a yellowish green midrib, a yellowish green abaxial surface, and light reddish petioles with the color extending onto the petiolules. The adaxial surface is typically glabrous (without hairs) while the abaxial surface and petioles have a downy pubescence. Leaflet venation is pinnate, depressed adaxially and expressed abaxially, with the nearly straight secondary veins extending to the margin. All leaves have axillary buds, but typically most new growth arises from the single and paired terminal buds. When soil becomes dry over summer, leaves become yellow and may fall off (in some years, quite early), even as fruits continue to mature. If leaves are lost during summer, additional leaves do not develop until the following spring.

Photo 3: Leaves and terminal inflorescences grow rapidly in early spring. Strap-like, light colored bracts and short brown bud scales are poised to drop off. Photo – March 29.

Reproductive buds produce both leaves and a terminal inflorescence, a panicle, attached immediately above the uppermost pair of leaves. From late March into April, for about two weeks, twenty or more upright flowers clusters grow along the rachis of each inflorescence. Each cluster bears one to five flowers on short pedicels (flower stalks), with larger clusters at the base of the panicles and single flowers near and at the top. Panicles bloom sequentially from base to apex and from the rachis outward.

Red buckeye produces both staminate flowers (fertile stamens and infertile pistil) and perfect flowers (both stamens and pistil fertile) in the same panicles. Staminate and perfect flowers have the same appearance, except styles of the perfect flowers are noticeably exserted. Perfect flowers occur at the lower portion of panicles and close to the rachis. As perfect flowers develop fruit, staminate flowers and their supporting pedicels, as well as other non-fruit-bearing portions of the inflorescence dry and drop off.

Photo 4: Peduncle occurs as a continuation of the branch below. Note early-developing axillary buds; the lower bud is already dominant. Perfect flowers, with exserted white styles, can be seen on left side of rachis. Photo – April 20.

Flowers are spectacular: to 1½ inches long, set in dull red, elongate tubular calyxes, tipped with five triangular lobes. The corolla is composed of two protruding upper and two protruding lateral petals with enlarged rounded apical portions and sharply narrower bases that disappear into the calyx. Upper petals are shorter with a larger rounded apical portion while lower petals are longer with a smaller apical portion. Color of rounded apical portions of petals varies from dark to light red with color of narrow portion being lighter red to yellowish. Rounded apical portion of upper petals flares upwards and backwards while rounded portion of lateral petals extends directly forward. Exterior of petals is about the same color as the calyx. The exposed portion of petals is about half as long as the calyx. Five to eight stamens have light yellowish green filaments supporting reddish anthers. Anthers open lengthwise to expose reddish pollen. Styles of fertile pistils are long, slender, very light reddish to white, and taper to pointed stigmas exserted well-beyond the anthers. Infertile pistils of staminate flowers are short and white. Petals and other internal flower parts are partially or totally covered with downy or twisted pubescence.

Photo 5: Display showing stamens (#1), petals (#2), calyx (#3), fertile pistil with ovary and style (#4), and an infertile pistil (#5). Note pubescence. Photo – April 7.

Fertilized flowers produce large (to 2 inch in diameter), irregularly shaped, ovoid, yellow-brown seed capsules that have thick, smooth, dull, leathery husks. Typically, only one to a half dozen fruits per panicle will reach maturity. In early fall, capsules split (dehisce) along two or three seams, allowing their one to three seeds to drop out. Individual seeds are generally rounded, but may have a peaked end (one seed per capsule) or be rounded with a flattened side or two (two or three seeds per capsule). Seeds are large and nut-like, an inch or more in diameter. The seed coat is shiny reddish brown with a light tan hilum, the scar left where the seed stalk has fallen away. Shrunken seed capsule walls and ultimately the entire inflorescence drop off during winter. Seeds are poisonous to humans.

Photo 6: Fruit capsules will dehice along seams to release seed. Thereafter, entire peduncles drop off. Inset photo shows germinated seed in mid-March. Main photo – Jul 28.

In a formal or natural garden, red buckeye would be a superb addition. It has interesting features throughout the year: showy late winter/early spring growth, spectacular flowers, opposite palmate leaves, intriguing fruit with unique seeds, and attractive winter-time structure of stout twigs and plump, handsome buds. Flowers provide an early food source for hummingbirds which, in turn, provide pollination. This shrub-trending plant can be nudged into a tree form by early removal of lower branches. A heathy tree can produce a large number of seeds which, with help from squirrels, can result in extra plants in the area. Trees in open areas may suffer wind damage due to heavy fruit load and may lose all leaves in mid-summer, due to drying soil.

One other buckeye species occurs naturally in Arkansas, the much larger Ohio buckeye (Aesculus glabra). Its greenish yellow flowers and spiky seed capsules help separate it from red buckeye. See previous article on Ohio buckeye. Occasional hybrids between red and Ohio buckeye can be found (these plants are called Aesculus ×bushii).

* A second variety of “red” buckeye, yellow buckeye (Aesculus pavia var. flavescens), found in west and central Texas, has same characteristics as red buckeye, except for its yellow flowers. Red and yellow buckeye hybridize naturally. 

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Celandine Poppy

Celandine poppy or wood poppy (Stylophorum diphyllum) of the Poppy (Papaveraceae) family is a herbaceous perennial that bears bright yellow flowers in early spring. The genus name is from the Greek for “style” and “bearing” in reference to the flower’s distinctively long style. The specific epithet is also from the Greek, for “two leaves,” in reference to the two opposite stem leaves. In the U.S., the species occurs from Michigan and Pennsylvania south and west to the northern counties of Arkansas, Alabama, and Georgia. In Arkansas, it is a species of conservation concern, occurring in a small north-central area of the Ozark plateaus. The common name “celandine” originates from its similarity to greater celandine (Chelidonium majus), a non-native species naturalized from Europe.

Preferred habitat of celandine poppy is deciduous woodlands on partially to fully shady slopes, bottomlands and streambanks, in rich, mesic soils. Roots consist of irregularly shaped, stubby, dark brown rhizomes with white to yellow, long, fleshy roots. Crowns of rhizomes have multiple buds that develop from year to year with growth scars remaining at the end of the growing season. New growth, appearing in late February, remains viable through early summer or longer, depending on soil moisture. Plants have basal leaves and a pair of opposite leaves on the floral stems. The sap is yellow and staining.

Photo 1: This 2-inch-tall rhizome segment has new emergent growth, scars from previous years’ growth, and dormant buds. Photo – late December.
Photo 2: New leaves appear in late February. Inset shows an earlier stage when protective bracts still surrounded new growth.

Deeply lobed basal leaves emerge directly from the rhizome and grow to 8 inches long (including 2½-inch petioles) and 5 inches wide. They are a medium green above and a pale silvery green below. Slender petioles are flattened on the upper side and rounded below, with basal flanges that support emerging leaves and the floral stem. The upper leaf surface is glabrous (hairless) while the lower leaf surface has long, dense, twisty, white hairs. Petioles are also hairy, especially on the lower side. Hairiness of leaves and petioles decreases with age. Venation of the upper leaf surface is slightly suppressed, that of the lower surface expressed. Secondary and tertiary veins divide repeatedly in jerky fashion into the lobes to produce a reticulated pattern. 

Floral stems, light to medium green (occasionally purplish), are terete (round) in cross-section with a scattering of long, white, twisty hairs. They bear a single pair of opposite leaves below the inflorescence. With the ascending stems maturing at about a foot long, the early flowers are positioned just above basal leaves, while later flowers are elevated well above. Floral leaves have the same appearance as basal leaves, except for their shorter petioles.

Photo 3: Flowering plant with many basal leaves and two floral stems, each with a single opposite leaf pair. Hairiness of leaves and stem can be seen. Photo – early April.

One to four slender pedicels, up to 2 inches long and with long scattered hairs, grow from between the stem leaves. Pedicels bear elongate-oval flower buds, nodding at first, that are protected by two densely hairy sepals. As buds turn upward, the corolla pushes out of the enclosing sepals, which then drop off.

Photo 4: A pair of developing stem leaves subtend an umbel consisting of a flower bud on right, a flower on left and a developing seed capsule at center. Note knobby stigma of flower and spent brown stigma atop the capsule.

Showy flowers, up to 2 inches across, in early spring may be present for two or more weeks. Four bright yellow, bowl-shaped petals, typically touching or slightly overlapping, have broad, rounded, crinkly apexes and narrowing bases. The pistil comprises a roughly-textured, knobby stigma on a short stout style above an elongate-ovoid, four-chambered ovary. Yellow hairs cover the ovary. A large number of stamens, positioned in a dense ring around the ovary, have slender, light yellow filaments topped with round, flattened, golden yellow anthers. Flowers (with no nectar) can be self-pollinating.

Photo 5: Bright yellow petals surround a ring of golden yellow stamens. Stigma and ovary are prominent.

With fertilization, style and stigma shrink as the ovary quickly enlarges to an inch-long capsule that dangles near the basal leaves. Capsules mature in late spring, turning inside-out as they dehisce into four segments that fall away. The small, dark brown, shiny, ovoid seeds have white elaiosomes along one edge–these are food for ants that disperse the seeds.

Photo 6: Display of capsules, seeds and upper and lower surfaces of basal leaves. Seeds have white elaiosomes along one edge. Note that hairiness of these mature leaves has been mostly lost. Photo – early May.

For a garden, celandine poppy would provide strong character with its distinctive leaves and bright yellow flowers. This species spreads slowly by short rhizomes, but may be fairly aggressive due to self-seeding in favorable sites. Excess plants can be easily removed. It is avoided by deer and rabbits.

Note: The cultivated, non-native, aggressive greater celandine (Chelidonium majus) is vegetatively hard to distinguish from celandine poppy, but it is not currently recorded as escaped in Arkansas. 

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Woodland Phlox

Woodland phlox, blue phlox or wild sweet William (Phlox divaricata ssp. laphamii) of the Phlox (Polemoniaceae) family is the first phlox to bloom in the spring in Arkansas. The genus name is Greek for “flame,” in reference to many species of the genus with strongly colored corollas. The specific epithet, from the Latin, refers to the clonal “spreading” of the plant or possibly to the spreading branches of the inflorescence. The subspecies name honors Wisconsin scientist Increase A. Lapham.  The species occurs from Texas to South Dakota, thence east and south to the Atlantic and Gulf Coasts. In Arkansas, it occurs statewide.

Woodland phlox grows in rich, well-drained, mesic, sandy to rocky soils in deciduous woodlands, with full or partial shade. Plants also grow in more sunny sites that have dependable moisture, such as stream banks. With prevailing dry conditions, plants may lose leaves and go dormant. 

Stems and pedicels are covered with a dense short, soft, white pubescence, which lessens with time. New stems and pedicels tend to be purplish, becoming green with age. They emerge from shallow, uniformly-sized, slender white roots. There are two stem types.

One stem type produces the inflorescence, referred to herein as a “floral stem.” Floral stems grow to about 14 inches and bear short branches within the inflorescence. They emerge in early winter and die off after fruit matures.

A second stem type, referred to herein as a “clonal stem,” is initially erect, but becomes reclined with new apical growth. As the stems elongate, the older, lower leaves drop off. The leafless portion, surviving over a number of years, may be from an inch to several feet long. As this leafless portion becomes covered with duff, long, slender, white roots and stems emerge from the leafless leaf nodes. Over time, intertwined clonal stems may form mats of evergreen leafy stem apexes.

Photo 1: Floral stems appear in early winter with flowers reaching anthesis in March. Several broad-leafed clonal stems can be seen on the left side of photo.

Leaves of both stem types are similar in that they 1) are in opposite, widely spaced pairs set at 90 degrees to each other (decussate pairs), 2) have a medium green adaxial surface and a lighter green abaxial surface, 3) are sessile to clasping with bases that meet around the stems, 4) have scattered pubescence above and denser shorter pubescence below, and 5) have entire margins. Also for both stem types, pinnate leaf venation consists of a straight, skinny, sharply recessed midrib above and a strongly expressed midrib below, with off-set secondary veins that fade into obscure tertiary veins. The base of the leaf blade ascends from the stem, while the remainder of the blade is flattened toward sunlight with a gentle up-folding along the midrib.

Leaf shape of the two stem types is different. Floral stem leaves are ovate-lanceolate (to 2½ inches long and ½ inch wide) while clonal stem leaves are broadly oval to ovate (to 2 inches long and 1 inch wide).

Photo 2: Floral stems have more-elongate leaves than clonal stems. Note pubescence of leaves and calyxes.
Photo 3: In August, only clonal stems remain. Inset shows a clonal stem in December that has leafy current-year growth and 4 to 5 years of growth that has produced roots and stems at leaf nodes (leaves having dropped off).

The inflorescence, which terminates a floral stem, first appears as a tight spiky cluster of medium green, closed, pointed calyxes and a few small subtending leaves. With growth, this single cluster expands into several loose clusters: a terminal cluster and a couple of upper, axillary clusters. These several small clusters form a rounded (2 to 3 inch wide) inflorescence with 20 or more flowers. Stems and pedicels, purplish, have a dense, short, white pubescence. As corollas approach anthesis, extending well out of the calyxes, they have long slender tubular throats that abruptly widen distally into a shorter, twisted spindle of tightly overlapped corolla lobes.

At anthesis, corolla lobes spread to about one inch wide, with a “smooth” coloration of various shades of blue, lavender and blue-violet. A dark blue to purplish color at the throat entrance is enhanced by being outlined by a lighter shading. Interior and exterior of the throat are a similar dark color. Lobes, with a rounded to slightly peaked apex, are obovate (broader at apex and a wide taper to base) and slightly overlapped. Calyxes, covered with spiky, sticky pubescence, have short cupped bases that are rimmed by five very long, lanceolate lobes. All flowers of a plant bloom at about the same time with bloom period extending over two weeks.

Photo 4: Tightly wrapped corolla lobes unfurl to expose a dark throat. Note the beautiful pinwheel-like overlapping arrangement of the lobes when still in bud, as well as the long teeth of the calyxes and long pubescence of calyxes compared to that of stems and pedicels. Photo – mid March.
Photo 5: This young plant has many floral stems and several clonal stems (to the left and below).

Flowers have five stamens and a pistil, hidden within the corolla tube. Stamens are fused to the tube (rather than to the tip of the pedicel, i.e., the receptacle) and of varying lengths. They have white filaments supporting elongate anthers that produce bright yellow pollen. The style, set on a smooth green ovary, is pale green with a three-part spreading stigma. Ovary, style and stigma are short and about equal length. With fertilization, the ovary becomes a three-chambered, smooth, ovoid fruiting capsule that produces a few seeds. Capsule length is less than ⅛ inch.

Photo 6: Flowers have five adnate stamens of unequal length that bear elongate anthers. With calyx partially and corolla tube fully removed, the pistil, comprising ovary, style and stigmas, is revealed.

Woodland phlox is an ideal plant for shady natural areas, rock gardens and shade gardens that have fertile mesic soil. Its mass flowering in late winter is an early sign of winter’s imminent departure. Clonal colonies and newly seeded plants are not aggressive. With shallow clumping roots, sweet William can grow well with other native species. It may be eaten by deer and rabbits.

Other species of the genus that occur in Arkansas: 1) broad-leaf phlox (Phlox amplifolia), 2) sand phlox or cleft phlox (Phlox bifida – two subspecies), 3) annual phlox (Phlox drummondii), 4) smooth phlox (Phlox glaberrima), 5) garden phlox (Phlox paniculata), 6) downy phlox (Phlox pilosa – two subspecies), and 7) moss phlox (Phlox subulata).

Characteristics of woodland phlox that help separate it from these other species are its 1) broad leaves and sterile clonal stems, 2) hidden stamens, 3) broad corolla lobes with rounded to slightly peaked apexes, and 4) lack of a tap root.

Note: Phlox divaricata ssp. divaricata, another recognized subspecies (not known to occur in Arkansas), has very similar characteristics, except subspecies divaricata has apically notched corolla lobes. The range of subspecies divaricata partially overlaps that of subspecies laphamii, but subspecies divaricata primarily occurs farther east and north. Flower color of subspecies divaricata tends to be more pinkish.

Article and photographs by ANPS member Sid Vogelpohl

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