Know Your Natives – Butterfly Pea

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.

Butterfly Pea - Clitoria marianaPhoto 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.

Butterfly Pea - Clitoria marianaPhoto 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.

Butterfly Pea - Clitoria marianaPhoto 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.

Butterfly Pea - Clitoria marianaPhoto 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.

Butterfly Pea - Clitoria marianaPhoto 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.

Butterfly Pea - Clitoria marianaPhoto 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.

Butterfly Pea - Clitoria marianaPhoto 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

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Know Your Natives – Showy Partridge Pea

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.

Showy Partridge Pea - Chamaecrista fasciculata var. fasciculataPhoto 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.

Showy Partridge Pea - Chamaecrista fasciculata var. fasciculataPhoto 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.

Showy Partridge Pea - Chamaecrista fasciculata var. fasciculataPhoto 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.

Showy Partridge Pea - Chamaecrista fasciculata var. fasciculataPhoto 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.

Showy Partridge Pea - Chamaecrista fasciculata var. fasciculataPhoto 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”.

Showy Partridge Pea - Chamaecrista fasciculata var. fasciculataPhoto 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

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Know Your Natives – Tall bellflower

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.

Tall bellflower - Campanula americanaPhoto 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.

Tall bellflower - Campanula americanaPhoto 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.

Tall bellflower - Campanula americanaPhoto 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.

Tall bellflower - Campanula americanaPhoto 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.

Tall bellflower - Campanula americanaPhoto 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. When capsules dry, stacked light tan seed are released from the top. The tiny seeds are flattened, smooth and oval.

Tall bellflower - Campanula americanaPhoto 6: Seed capsules of central triad flowers at top and mid-right of photo are developing as lateral pairs enter the flowering sequence. Note the bee collecting nectar, even before flower is fully open.

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 it’s own different genus, Campanulastrum, due to its unusual floral characteristics and lack of bell-shaped corollas.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Whorled Milkweed

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.

Whorled Milkweed - Asclepias verticillataPhoto 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.

Whorled Milkweed - Asclepias verticillataPhoto 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.

Whorled Milkweed - Asclepias verticillataPhoto 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.

Whorled Milkweed - Asclepias verticillataPhoto 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.

Whorled Milkweed - Asclepias verticillataPhoto 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.

Whorled Milkweed - Asclepias verticillataPhoto 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

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Know Your Natives – Self-Heal

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.

Self Heal - Prunella vulgarisPhoto 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.

Self Heal - Prunella vulgarisPhoto 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.

Self Heal - Prunella vulgarisPhoto 3:  Display showing upper and lower leaf surfaces along with a stem terminating with a flower cluster.  Leaves, stems and calyxes are pubescent.

Self Heal - Prunella vulgarisPhoto 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.

Self Heal - Prunella vulgarisPhoto 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.

Self Heal - Prunella vulgarisPhoto 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.

Self Heal - Prunella vulgarisPhoto 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

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Know Your Natives – New Jersey Tea

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.

New Jersey Tea - Ceanothus americanusPhoto 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.

New Jersey Tea - Ceanothus americanusPhoto 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.

New Jersey Tea - Ceanothus americanusPhoto 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.

New Jersey Tea - Ceanothus americanusPhoto 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.

New Jersey Tea - Ceanothus americanusPhoto 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.

New Jersey Tea - Ceanothus americanusPhoto 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

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Know Your Natives – Western Daisy

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.

Western Daisy - Astranthum ciliatumPhoto 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.

Western Daisy - Astranthum ciliatumPhoto 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.

Western Daisy - Astranthum ciliatumPhoto 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.

Western Daisy - Astranthum ciliatumPhoto 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.

Western Daisy - Astranthum ciliatumPhoto 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.

Western Daisy - Astranthum ciliatumPhoto 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

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Know Your Natives – Hairy Phacelia

Hairy phacelia (Phacelia hirsuta) of the Borage (Boraginaceae) family [formerly of the Waterleaf (Hydrophyllaceae) family] is a beautiful annual forb with blue flowers.  In the U.S., it is found naturally in Arkansas, Louisiana, Texas, Oklahoma, Kansas, and Missouri, as well as introduced in Kentucky and Pennsylvania.   In Arkansas, it is found throughout much of the state but sparser in the Mississippi Alluvial Plain.  Its habitats include rocky to sandy, moist soils in open woods and woodland margins, as well as in prairies, glades, and along roadsides.  The genus name is from Greek for “bundle”.  The specific epithet is from Latin for “hairy”.  Another common name is “hairy scorpion-weed”.

Hairy phacelia, whose basal leaves appear in late winter, develops a main stem and several long to short secondary stems.  The longest secondary stems grow from lower leaf axils of the main stem, with shorter stems growing from mid-stem axils.  Plants have a tap root and a few fibrous roots.  The main stem and secondary stems reach a similar maximum height of up to 1 to 1½ feet.  Stems, which are weakly erect, are yellowish-green with the lower portion having a reddish cast.  Stems are very hairy (hirsute).

Hairy Phacelia - Phacelia hirsutaPhoto 1:  In this April 2nd photo, several secondary stems have developed and developing inflorescences can be seen at the ends of stems.

Alternate hirsute leaves, with three to seven leaflets or lobes, are widely spaced on a mature plant and are medium green on upper surfaces and light green on lower surfaces.  Leaves feel soft and venation is not especially distinct.

Lower leaves, which have long, grooved petioles, have blades from ¾ inch to 1¼ inch long, with maximum width of about ¾ inch.  These leaves typically have a lower lateral pair of opposite, oval leaflets and, higher up the leaf blade, one to three pairs of mostly opposite, lateral leaflets that may have widened bases, becoming lobes.  Additionally, a large, broad terminal lobe is partially cleft on both sides so that it is three-lobed.  Lower leaflets (or lobes) are set perpendicular to the rachis while upper lobes (including those of the terminal lobe) are angled toward the apex.   Lobes of these lower leaves may be wide or narrow with rounded tips.

Upper leaves (from mid-stem into the inflorescence), have blades that decrease in size up-stem to uppermost leaves that may be ¾ inch long and 3/8 inch wide.  Transitioning up-stem,  lobed leaves gradually change shape from petiolate to sessile and lobe blade tissue increasingly extends along the rachis.  The uppermost leaves have two or three pairs of lateral lobes that may be either narrow-rounded and angled toward the leaf apex or narrow-acuminate and out-flared.   The shape of terminal lobes is similar to lateral lobes.  Petioles of mid-stem leaves (when present) are wide and broadly grooved.  Smaller leaves are sessile.

Hairy Phacelia - Phacelia hirsutaPhoto 2:  Leaf display shows changing leaf shape from basal to upper stem leaves (left to right).  Note that leaves change from petiolate to sessile and from having some leaflets and lobes to having all lobes.

Inflorescences, in mid-spring, grow from uppermost leaf axils of main and secondary stems.  Appearing first as round clusters (or “bundles”) of compacted sepals, with growth, the coiled nature of the inflorescence becomes apparent.  Coils consist of a peduncle with up to twenty or more flowers alternately arranged along the upper side of the inflorescence axis (rachis).*  Flowers are each on a short pedicel.  Peduncles and pedicels have short hirsute pubescence.  As the coil straightens, flowers reach anthesis from lowermost to uppermost.  When fully straightened and the last flower has bloomed, the inflorescence may be 3 inches long.   The entire plant continues to stretch out (grow) until the final flowers have bloomed.

Hairy Phacelia - Phacelia hirsutaPhoto 3:  Developing inflorescence appears as rounded clusters of loose, hirsute sepals at ends of stems.

Flowers, about ½ inch in diameter, have a deeply divided calyx with five long, narrow, spreading lobes with hirsute exteriors, and a bowl-shaped corolla notched to create five broadly-triangular but rounded lobes.  The exterior of the corolla is pubescent.  Corollas are typically a light blue to lavender overall, but may have a lighter or white center.  Just below mid-corolla, ten dark purple, round to three-sided spots encircle the flower’s center, two spots below each lobe.  These purple spots are surrounded by a haze of lighter color.  Five spreading stamens have white filaments, with anthers at first bearing light yellow pollen that become black.  Filaments, adnate at the base of the corolla, are covered by long radiating white hairs.  The pistil, also white, has a forked and pointed style whose stigma does not become receptive to pollen until after the pollen from the same flower has been shed (protandry–an adaptation that reduces self-pollination).   Stamens and pistils, all about the same length, extend slightly beyond the rim of the corolla.  A light green, superior ovary, also hirsute, has the shape of an elongated, round cone.

After producing seed capsules containing a small number of brown seeds, these annual plants quickly die.

Hairy Phacelia - Phacelia hirsutaPhoto 4:  Flowers reach anthesis at the top of a coil in sequence (from left [bottom of coil] to right [top of coil] in this photo) as coil straightens.  “Newest” flower at right bears pollen.  Forked styles can be clearly seen in the lower two flowers.

Hairy Phacelia - Phacelia hirsutaPhoto 5:  In this May 1st photo, plant is nearing the end of its life cycle.  Plant being collected by botanist Eric Sundell (a reviewer of these articles), accompanied by Milanne Sundell.

In addition to hairy phacelia, six other native phacelia species occur in Arkansas.  Hairy phacelia is the most common and widespread.  Three of the others are rare to very rare in the state and are tracked by the Arkansas Natural Heritage Commission.  Hairy phacelia can be distinguished from the other six by several characteristics, including 1) high degree of pubescence and 2) light blue to lavender, bowl-shaped, 10-spotted corollas, 3) stamens and pistils that are only slightly exserted from corolla, and 4) rounded, non-fringed corolla lobes.

Another species in the borage family that can occur in the same habitats as hairy phacelia and with some similar characteristics is “large-flower baby-blue-eyes” (Nemophila phacelioides).  It occurs in the west-central part of the state.

  • This inflorescence style is referred to as a scorpioid (resembling the coil of a scorpion’s tail) or helicoid cyme which is typical of the borage family and the source of one of the general common names, “scorpion-weed”, for some members of the genus Phacelia.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Wild Geranium

Wild geranium (Geranium maculatum) of the Geranium (Geraniaceae) family is an herbaceous woodland perennial that blooms in early spring.  In the U.S., this species is found from Louisiana and Oklahoma to Florida and north to North Dakota and Maine.  In Arkansas, it is found primarily in the highlands of the northwestern half of the state.  The genus name is based on a Greek word meaning “crane” in reference to the shape of the plant’s fruit which resembles a crane’s bill.  The specific epithet means “spotted” in reference to leaf spots that may or may not be present.  Other common names include spotted geranium, spotted crane’s-bill and wood geranium.   Preferred habitats are wind-protected, lightly shaded, mesic deciduous woodlands and borders with various well-drained soils, but it may be found in sunny sites with consistent moisture.  Plants may wilt on hot, windy spring days and may enter early dormancy if drier conditions persist.

Wild geranium, a long-lived plant, has stout, dark-colored, round, shallow, rough rhizomes with a light orange interior.  Nubs develop along the sides of rhizomes that may grow into rhizome branches.  Fibrous roots grow from the lower sides of rhizomes.  Leaf and stem growth originates at the tips of rhizomes.  With mature plants having many growth tips on relatively short rhizome segments, a mature plant develops a rounded mound of leaves.  A plant may have a spread of 2 feet or more and reach a height of 1½ feet tall.

Wild Geranium - Geranium maculatumPhoto 1:  A partial rhizome and plant (detached from main rootstock at light orange area).  This rhizome segment has several branches, including a small branch on the right side.

The first leaves to appear in spring are basal leaves.  The largest basal leaves, on the periphery of the leaf mound, may be 6 or more inches wide with a petiole that is 7 or more inches long.  Leaves, medium green on upper surface with a similar dull green lower surface, are finely pubescent on the upper surfaces as well as along the veins of lower surfaces.  Basal leaves have a terminal lobe and two lateral lobes on each side, arranged in palmate fashion.  The five lobes have wedge-shaped bases with wider mid-sections which gradually narrow in width to acutely rounded apices.  Margins, which are entire near lobe bases, have short to long crenulations from mid-leaf to the leaf apex.  The five lobes join together shortly above the petiole.  The petiole is attached to the underside of the leaf blade at the leaf margin.  Individual leaves and petioles are weak, but remain upright due to support from nearby leaves.  The interior of the leaf mound is filled with smaller leaves.  Basal leaves remain into late fall.

Wild Geranium - Geranium maculatumPhoto 2:  A relatively small young plant.  Note wide uncleft area at center of leaves as well as flower buds making their appearance (see top center and lower right).  White flowers in upper left are those of rue anemone (Thalictrum thalictroides).

Shortly after the leaf mound has formed in late winter to early spring, clusters of football-shaped flower buds become visible across the leaf mound, as stout, unbranched and heavily pubescent floral stems rise above the basal leaves.  Stems, five sided (more pronounced on larger stems) with downward-trending prominent pubescence and one or more pairs of cauline (stem) leaves, grow from rhizome tips surrounded by basal leaves.  Stems continue to grow until buds are well above basal leaves and the lowermost pair of cauline (stem) leaves is positioned just above the basal leaf mound.  As flowers reach anthesis, stems (with inflorescence) may have a total height of 16 inches with 10 of those inches below the lowermost cauline leaf pair.  The lowermost pair of cauline leaves subtends two or three erect, light green to reddish secondary stems that may be 5 inches long.  These secondary stems, in turn, support one to three peduncles (stalks of inflorescences) from which several pedicels (stalks of flowers) grow that are also subtended by leaf pairs.  Leaves of the lowermost cauline leaf pair have the same appearance and size as basal leaves, but with petioles that are from ¾ inch to 4 inches long.  Leaves that subtend pedicels have the same texture as other leaves, but appear three lobed at about 2 inches wide, with short petioles or perhaps sessile.

Wild Geranium - Geranium maculatumPhoto 3:  A single pair of cauline leaves subtends an upper secondary stem and two lower peduncles.  Note the small leaves on the secondary stem and bracts at bases of stems, peduncles and pedicels.

At anthesis in early spring, 1½-inch-diameter, upward-facing flowers are light pink to lavender with whitish centers.  Flowers have five obovate overlapping petals and five light green pubescent, slightly ridged and elongate sepals.  Sepals have acute apices that terminate in needle-like tips (cuspidate).  Petals, with broadly rounded upper margins, surround ten stamens and a pistil.  Stamens, connecting to the flower’s axis below a hairy ovary (superior ovary) of five carpels, have white slender filaments with elongate yellow anthers that bear yellow pollen.  Pistils have a long slender whitish style that branches into stigmas, spread wide and curved backwards.  Styles attach to the smooth, round-elongate, green sections of the ovary.  Individual flowers, up to about ten to fifteen per stem in pairs or in loose clusters, are in bloom for one to two days.  Total bloom time for a plant extends over about three weeks.  Cauline leaves wither in late summer, well after seeds have dispersed.

Wild Geranium - Geranium maculatumPhoto 4:  Flowers, changing from pink to lavender, have widely flared, overlapping, obovate petals.

Wild Geranium - Geranium maculatumPhoto 5:  Display showing flower buds (lower right), front and back of flowers and a flower past bloom (lower left).  Note five-branched, back-curved stigmas.

After fertilization of a flower, the lower portion of the style quickly elongates and the five seeds–one in each ovary chamber–enlarge so that the ovary becomes knobby. The stigmas wither so that a crane’s-bill-like fruit is formed.  The fruit, an inch or more long, matures and dries to a dull dark brown rigid capsule.  Five dark brown oval seeds, resting just above the drying sepals, are tightly held in place, capped by the ovary wall, which bears five long thin arms (springs) aligned along the style and firmly attached just below the dried stigma.  When the seed-bearing structure is dry, each cap and associated spring-loaded arm snaps upward.  With this instantaneous snap, the seed is catapulted a number of feet away from the plant.   Caps and arms, now curled backwards, remain attached at their upper end to a dried woody style.

Wild Geranium - Geranium maculatumPhoto 6:  The flower at lower position in display (sepals and anthers removed) exhibits a prominent pistil prior to spreading of stigma.  The two fruits (sepals removed) show the closing of the stigma (more mature fruit at top of display), strong growth of their “bills” and enlargement of ovules.

Wild Geranium - Geranium maculatumPhoto 7:  In this display, the central stem bears a green immature fruit and a brown fruit that is poised to launch its five seeds.  Seeds (examples on left) of the other two stems have been launched with caps and arms curled backwards.

For a partially sunny woodland garden, wild geranium is effective as a long-lived plant that is easy to cultivate.  It has attractive form and foliage and showy flowers and fruit so that it is appropriate for specimen plants or as a groundcover.  It is easily propagated by division.
The only other widely occurring native species of the genus found in Arkansas is Carolina crane’s-bill (Geranium carolinianum var. carolinianum).  This is a small weedy annual/biennial species with small palmate leaves and purplish pink flowers.  Another Arkansas native species known from only Miller County is Texas crane’s-bill (Geranium texanum).  Four non-native species of the genus are also found in the state.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Fire Pink

Fire pink (Silene virginica) of the Pink or Carnation (Caryophyllaceae) family is an herbaceous woodland perennial with bright red flowers.  In the U.S., fire pink is found from Florida to New York and westward to northeast Texas, Kansas and Minnesota.  In Arkansas, it occurs across the highlands of the northwestern half of the state.  Its habitat includes partially sunny sites of open woods with various dry to mesic soils where ground vegetation is sparse.

This species occurs as single plants or small colonies of scattered plants.  The base of the plant comprises a woody branched caudex that rests directly on the soil surface, along with a branched tap root, and white fibrous roots growing directly from the caudex.  The caudex of a mature plant has multiple growth points.

Appearance of the basal leaves varies depending on the plant’s age and the season.  New plants have egg-shaped leaves with a constricted base (obovate).  Mature plants have rosettes of basal leaves that are spoon-shaped (spatulate) with narrow elongated bases.  Fresh basal leaves have a dark green upper surface and a lighter green lower surface.  Margins are entire (without lobes or teeth), but may be crinkled.  Although leaf surfaces are glabrous (hairless), hairs occur along the margins (ciliated margins), but only from midleaf (short hairs) to leaf base (long hairs).  Basal leaves that survive over winter assume a reddish color.

Fire Pink - Silene virginicaPhoto 1:  These multiple leaf rosettes are growing from a single caudex.  Flowering stems are poised to grow as can be seem on the left side.  Photo in late February.

Flowering stems grow from centers of leaf rosettes in late winter to early spring.  These main stems, which may grow to a foot or more long, have dense short pubescence.  Initially, stems grow outward, nearly parallel to the ground.  As they mature, stems arch upward so that the plant in full bloom exhibits an open structure with long, slender, wide-spreading to erect stems.  Main stems bear two to six pairs of opposite, clasping leaves (the cauline leaves) with leaves of lowermost pairs being similar to basal leaves, but with wider bases.  Lower leaf pairs are spaced up to about 4 inches apart.  Upper leaf pairs, which become closer together and much smaller toward top of stems, are somewhat ovate with gently acuminate tips.   Lowermost cauline leaves may be five inches long while upper leaves may be only ¼ inch long.  Stems, round in cross-section (terete) and hollow (fistulose), may have a mature length of about 1½ feet.   Stems tend to be reddish on their sunny side and green on shaded side.

Fire pink’s stems have a growth pattern which could be called “pattern-of-three”, that is, leaf pairs at about mid-stem typically subtend a combination of secondary stems and flowers that total “three”.  At about mid-stem, leaf pairs subtend two secondary stems and one flower located between the two stems (referred to herein as “axillary flower”).  When this “pattern-of-three” includes two secondary stems, one of the stems is dominant and it may produce an additional stem.  All stems terminate with a group of three flowers.  On a main stem or secondary stem, the first flower to reach anthesis is the lowermost axillary flower, followed by terminal flowers of secondary stems.  Up to about 30 flowers may occur on one main stem.

Fire Pink - Silene virginicaPhoto 2:  A flowering stem with widely spaced pairs of leaves on its lower portion.  First flowers to open are axillary flowers between two secondary stems, as shown.  Note additional stems just appearing.

Flowers, occurring on separate pedicels, have calyxes composed of five fused sepals that are reddish to purplish on their sunny side while flowers are in bloom, but changing to medium green as flowers fade.  Individual flowers, which may remain showy for a week or more, are up to 1 inch long (calyx included) with a flat-faced corolla that has a width up to 1½ inches.  The corolla comprises five vibrant red petals that are evenly spaced in star-fashion.  Petals, as seen from corolla face, are elongate, each with a characteristic deep terminal notch* and often with short side wings angled toward the tip.  Petals have a sharp flexure where they transition from the corolla face to a tight floral tube formed by the overlapping of narrow petal bases.  Most of the floral tube is within the inch-long calyx tube, but about a fourth of its length is outside.  At the petals’ flexure points, they have two short red upward-extending flanges, so that five petals, as a unit, produce a small corona that encircles the floral tube.  The outside of the petals and exterior of the floral tube are a duller shade of red.  Flowers have ten light red stamens that are adnate to the short stalk of the elongate, yellow-green, cylindrical ovary hidden deep in the calyx.  Stubby, elongate, two-lobed anthers, balanced lengthwise at the tips of filaments, are at first light yellow but become grayish as pollen is released.  Three light red slender styles, arising from the apex of the ovary, have a sloped stigmatic surface.  The calyx tube, with five pointed teeth, is marked with 10 darker longitudinal ridges.  Within the confines of the calyx, bases of petals, stamens and pistils are white.

Stamens and pistils become exserted in sequence: First, the five stamens adnate to the petal bases; second, the five stamens attached in between the petal bases; and third, all three styles.  By the time the second set of stamens becomes exserted, stamens in the first set have lost their anthers and filaments have become back-flared and wilted.  Similarly, by the time the styles become exserted, stamens of the second set have also declined. This sequence of anther and style/stigma development lessens chances for self-pollination.

Fire Pink - Silene virginicaPhoto 3:  Even with a dozen main stems, the inflorescence is very open.

Fire Pink - Silene virginicaPhoto 4:  The corolla and corona are the same vibrant red.  As shown, all ten stamens have emptied their anthers of pollen and twisted backwards as stigmas become receptive to receiving pollen from a different flower.  Note the enlarged calyx behind the corolla.

Fire Pink - Silene virginicaPhoto 5:  In the flower shown with petals, two sets of five anthers are exserted while styles have not yet appeared.  The two flowers without petals show styles emerging with stamens in decline (lower center) and styles fully exerted with receptive stigmas, while stamens have wilted (upper left – note enlarging ovary).  A ridged calyx (center) is also shown.

Upper portions of flowering stems have short, glandular hairs that cause the upper stem, upper cauline leaves and caudex exterior to feel sticky (viscid).  The greatest degree of stickiness occurs nearest the flowers.  Small flying insects are often caught on the sticky surfaces and ants cannot reach the nectar.

Upon completion of bloom, calyxes become swollen, point downward and dry to a light tan.  When dry, calyx teeth roll well back so that the upper portion (now hanging down) of the calyx has a gaping hole.  The placenta of the fruit within the calyx disintegrates and the seeds readily fall out.  The small round, tan to brown seeds, with a tight C-shape, are covered with minute crowded knobs.  With flowering completed, stems gradually disintegrate, with basal leaves remaining through the summer into winter.

Fire Pink - Silene virginicaPhoto 6:  As calyxes dry, teeth roll back and seeds easily drop out.

For a garden or natural area with partial sunlight and good drainage, fire pink is an excellent year-round, well-behaved, low-maintenance choice that puts on a spectacular show of striking spring color.  Flowers are a favorite of hummingbirds, which are a principal pollinator.  Should past-bloom stems be untidy as they decline, they can be easily removed.

Eight additional species of the genus are known to occur in Arkansas of which the only one with red flowers is royal catchfly (Silene regia).  Royal catchfly is a taller clump-forming, heavily pubescent plant with more closely spaced, numerous cauline leaf pairs and un-notched petals.   Starry campion (Silene stellata), a white flowering species of the genus, has been previously addressed in this series of articles.

*The word “pink” relates to the cutting of cloth with pinking shears to prevent threads in woven cloth from unravelling.  The ends of fire pink’s petals appear to be “pinked”.

Article and photographs by ANPS member Sid Vogelpohl

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