If you enjoyed the webinar series offered by the Arkansas Native Plant Society in May, then you may be excited to find out that we will be continuing these webinars monthly for the remainder of the year, and hopefully beyond.
The first webinar in our monthly webinar series will be Glades of Arkansas with Brent Baker, scheduled for this Saturday, June 5th, 10-11am.
Program Description: In this webinar Brent will discuss what glades are, as well as the different types found in Arkansas and where they occur. He’ll also highlight glade plant species in general and discuss some species that are unique to certain types of glades.
Speaker Bio: Brent Baker is a botanist with the Arkansas Natural Heritage Commission, an agency of the Division of Arkansas Heritage within the Department of Parks, Heritage and Tourism, where he has worked for nearly twelve years to monitor and discover new populations of rare plants in the state and to conduct botanical inventories of the state’s System of Natural Areas and other ecologically significant lands. He is also the collections manager for the Commission’s Herbarium, a collection of preserved and labeled plant specimens for documentation, reference, and scientific study. Brent holds a bachelor’s degree in environmental science and a master’s degree in biology with an emphasis in botany, both from the University of Central Arkansas. He was a member of the Arkansas Vascular Flora Committee and was one of the editors of the Committee’s Atlas of the Vascular Plants of Arkansas, published in 2013. Brent is an eighteen-year member and former president of ANPS. In his free time, Brent enjoys native plant gardening and working on habitat restoration on his property outside of Dardanelle.
Just a friendly reminder that you will need to have the Zoom software/app installed on your computer, tablet, or smartphone in order to use this link and view the webinar.
Long-Flower Cornsalad (Valerianella longiflora) of the Cornsalad (Valerianaceae) family is an intruigingly branched, herbaceous annual with white flowers with long purple floral tubes. The genus name is the diminutive of Valeriana, the type genus of the Valerianaceae, a name honoring the Roman emperor Valerianus. The specific epithet refers to the flowers’ long floral tubes. In the U.S., the species is endemic to east-central Oklahoma and west-central Arkansas. In Arkansas, more specifically, it occurs in the western Ozark Plateaus, Arkansas River Valley and Ouachita Mountains. The common name “Cornsalad” highlights the use of young plants of some of the species in salads, primarily the non-native Valerianella locusta. Habitat preference is well-drained rocky to sandy soils in full to mostly sunny sites, such as short-grass areas of prairies and glades, woodland openings, and mowed areas of fields and highways.
Taprooted plants first appear as low-growing rosettes of simple spatulate leaves, much like those of other species of Cornsalad. They will reach a height of about 16 inches. A single erect stem divides into paired opposite branches (dichotomous branching) with the final division terminating in the inflorescence. The 2-6 pairs of branches are each subtended by an opposite pair of leaves. The angle between paired branches is fairly constant at about 30⁰ with pairs being rotated by up to 90⁰ from one pair to the next. Stems are hollow, glabrous, and yellowish green, with purplish shading where exposed to more sunlight. They are slightly ridged making them hexagonal in cross-section. Colonies of the plants tend to be about the same height with branches intertwining with other forbs and grasses.
Opposite, clasping leaves fully encircle the stem at their base. Leaves below the lowest pair of branches (“lower leaves”) tend to be of similar size, to 2½ inches long and ⅜ inch wide. Leaf pairs above the lowest pair of branches (“upper leaves”) decrease quickly in size to the point that those subtending the peduncles (stalks of the inflorescence) may be ⅛ inch long and 1/16 inch wide. While shape of lower leaves changes from spatulate to oblong, upper leaves are mostly oblong, grading to lanceolate. The soft yellowish green leaves have entire (uncut) margins and mostly rounded apexes. Pinnate venation is obscure except for the lighter colored and slightly recessed upper midvein and expressed lower midvein.
The Cornsalads have cymose inflorescences that are extremely structurally complex. The following guided tour of the Long-Flower Cornsalad inflorescence is probably best understood by examination under the bright light of a dissecting microscope: A plant with four stem/branch divisions would have 16 peduncles (see Photo 2), growing to ½ -1 inch long, subtended by the uppermost pair of leaves. Each peduncle terminates with a flat-topped floral cluster (“primary cluster”) with a mature base that is from ½ inch long and ¼ inch wide, with that size expanded by the flower cluster. Primary clusters bear about 16 flowers divided into two adjoining clusters (“secondary clusters”). Secondary clusters are subtended by a matched pair of small broadly lanceolate (⅛ inch by 1/16 inch) “basal bracts” along with similarly shaped and sized “floral bracts”. Floral bracts, which subtend flowers at the exterior of clusters, are immediately above and in contact with the basal bracts. In addition to the bracteate flowers, single un-bracteate flowers also occur: 1) between the peduncles at the tip of the branch and 2) between paired secondary clusters. Basal and floral bracts are oval with a sharp tip and spiky ciliate margins (see Photo 3). Peduncles and bracts are a pale green with bracts, especially their tip and margins, highlighted in purple. A plant’s overall inflorescence may be to 10 inches wide, depending on habitat and plant crowding.
Flowering, over a month in April-May, begins with the bractless flower and continues with the bracteate flowers. In bud, the corolla has a white spherical shape atop a long purple tube. Fully open flowers have five widely flared (to 1/4 inch wide), obovate, white corolla lobes and a 3/8 inch long and less than 1/64 inch wide corolla tube. The gynoecium comprises a single pistil (stigma, style and ovary), the androecium 3 stamens, inserted on the corolla tube. Flowers are epigynous––the ovary is inferior, with the corolla attached at its summit. When flowers initially open, the elongate white anthers, center-balanced on the extremely slim filaments, are held directly above the half-hair-sized style. Once pollen has been shed, filaments reflex tightly between the corolla lobes (becoming purple). With stamens in this position, the extremely tiny stigma trifurcates to expose stigmatic surfaces.
With fertilization, 1 of a flower’s 3 carpels develops a viable seed (the other 2 are infertile) as the plant dies. The almost round and somewhat flattened, chubby fruits (less than ⅛ inch across) have a smoothly rounded side and a side with a longitudinal groove. The unusual fruit shape is the product of the fertile middle carpel being bounded by compressed, parallel infertile carpels. The tawny brown seeds are glabrous.
For a garden or natural area, Long-Flower Cornsalad would be a welcome, showy annual plant, often seeding to a lovely colony. If self-seeding becomes a problem, spreading may be controlled by removal of excess plants before fruits mature. However, it would be ideal for a prairie setting where it can feely mix with other spring-blooming annuals and grasses. It provides nectar and pollen for small bees and flies. It is not favored by deer.
Six other species of the genus occur in Arkansas. Of the other six, Ozark Cornsalad (Valerianella ozarkana) has the most similar flowers, with long purplish tubes. Ozark Cornsalad may be distinguished primarily by its usually longer, three-angled, oblong fruits with three lines of pubescence (a form with smaller, rounded, glabrous fruits may sometimes be encountered). Ozark Cornsalad is found primarily in the Ozark Highlands, with scattered occurrences in the Boston Mountains and Arkansas Valley.
Article and photographs by ANPS member Sid Vogelpohl
Prairie Ragwort (Packera plattensis, formerly Senecio plattensis) of the Aster, Sunflower, or Composite (Asteraceae) family is an herbaceous perennial with felty, white stem hairs and attractive, yellow, radiate flower heads. The genus name honors Canadian John G. Packer, author of Flora of Alberta. The epithet refers to the range from which the species was first described: “of the Platte River region.” Prairie Ragwort is widespread within central U.S. from north-central Louisiana and central Texas north to Indiana and eastern Montana. Widely scattered populations also occur in the eastern U.S. In Arkansas, it is reported from throughout much of the state but appears to be more common in the Ozark Plateaus and the Arkansas River Valley. Habitats include various dry to mesic sandy to limy soils in prairies, fields and open woodlands. The species is also known as Prairie Groundsel.
Prairie Ragwort has erect flowering stems to 2 feet tall which are unbranched, except within the inflorescence. Stems grow from short, vertically oriented, perennial rootstocks which extend deeper into the soil with age and become roughened by encircling leaf scars. One to several slender taproots may be present along with string-like fibrous roots, all growing from the rootstock’s tapered distal end. String-like, near-surface, white stolons (same appearance as the roots) extend off the rootstock and give rise to clonal plantlets. These may be as far as a half-dozen inches from the parent. Apparently, rootstocks survive for only several years, but, with continual production of new plantlets, the plant is perennial.
The rootstock may produce 1-3 closely spaced, light green to basally purple, hollow stems, clothed in woolly pubescence. As they age, stems may become more or less glabrous above, except for patches of woolly hair in the leaf axils.
Plants have simple basal leaves. Early new leaves are oval to elliptic with later leaves becoming broadly lanceolate. Basal leaves, with long slender petioles, are dark green above and light green beneath. Early in the growing season, they have a dense mat of short appressed hairs (floccose pubescence). Oval leaves may be 6 inches long (including a 3½ inch petiole) and 1¼ inches wide, while lanceolate leaves may be 10 inches long (including a 5½ inch petiole) and 2 inches wide. Basal and stem leaves are shown in Photo 4. Leaves are firm to slightly leathery with the blade ascending along both sides of the midrib. Petioles are light green and grooved above, with the groove continuing along the leaf midvein. Basal leaves that grow later in the growing season are ascending to erect with the final leaves of the growing season being ground-hugging for surviving over winter months.
Mid-stem to upper-stem leaves are sessile and alternate, measuring 6 inches long and 2 inches wide, but quickly reduced in size distally into the inflorescence. The blades are deeply, pinnately cut into a half dozen or more lobes, with midribs between lobes slightly winged. Larger basal lobes clasp the stem. Blades are mostly glabrous with sparse hairs beneath.
The inflorescence consists of “radiate” flowerheads––comprising both ray and disc flowers––arranged in corymbs that are further aggregated to form a compound corymb with all the heads at about the same height. As in virtually all composites, disk flowers of a head bloom centripetally––the outer, peripheral florets bloom first. In contrast, the central head of the corymb (as well as the central corymb of the compound corymb) initiates blooming––i.e., the heads bloom centrifugally. With each corymb having up to about 10 flowerheads, the entire cluster may have 40+ flowerheads. Flowering continues for about a month (April-May) before plants are overshadowed by later competitors, including prairie grasses.
Flowerheads, to ¾ inch wide, are subtended by a rounded-elongate 1/4-inch-long involucre of a single series of 16± appressed, green, lanceolate, tomentose bracts (phyllaries). Heads comprise 80± central yellow disk florets and a dozen or so outer yellow ray florets. The perfect tubular disk florets (with pistil and stamens) have five short triangular flared corolla lobes. The pistillate ray florets (no stamens) bear ¼ inch long, strap-like ligules above their short tubes. Ovaries are surmounted by a pappus of erect hair-like bristles that later will aid in fruit dispersal. Disk florets have 5 stamens, the anthers of which form a ring around the developing style. As the style elongates through the anther ring, it plunges the pollen out of the anthers, transporting it to the surface of the head where it is available to pollinating insects. Thereafter, the style bifurcates and recurves to expose two elongate stigmas which capture pollen on their sticky surfaces from other florets.
Ovaries of fertilized florets quickly develop into single-seeded, non-dehiscing fruits (achenes). The elongate brown achenes, with ribbed sides, are about ⅛ inch long with a spreading “parachute” of many ascending straight white bristles (the pappus). Wind dispersal continues over a month or so.
For a shady or sunny garden, Prairie Ragwort has a nice height, interesting leaves, and showy flowers that reach peak bloom when many springtime flowers have faded. Plants provide nectar and pollen to visiting insects. On the other hand, with plants being stoloniferous, containment of a colony may become a challenge. Disposal of stems before seed dispersal would limit establishment of new colonies. It may be more appropriate for a prairie garden where it may be controlled by competitive grasses. The foliage is toxic to mammals (pyrrolizidine alkaloids).
Six additional species of ragwort are known to occur in Arkansas. Butterweed (Packera glabella) and Great Plains Ragwort (Packera tampicana) are annual species. Round Leaf Ragwort (Packera obovata) has glabrous stems and obovate basal leaves often with purple undersides. It usually is found in shaded, moister woods and can form large colonies. Golden Ragwort (Packera aurea) has glabrous stems and large heart-shaped basal leaves on long petioles. It grows in wetter areas, often associated with seeps, springs, or banks of spring-fed streams. Woolly Ragwort (Packera tomentosa) has tomentose pubescence covering leaves and the entire stems. Balsam Ragwort (Packera paupercula) may be the most similar species. This species is described as being highly variable both morphologically and ecologically and is still relatively little understood in Arkansas, so a comparison is difficult. It seems to have narrower, more elongate basal leaves and apparently flowers later than most of the other ragworts, including Prairie ragwort. More study of these species is needed.
Article and photographs by ANPS member Sid Vogelpohl
Early Buttercup (Ranunculus fascicularis) of the Buttercup (Ranunculaceae) family is a late winter, herbaceous perennial, with glossy yellow flowers and tuberous, thickened roots. The genus name is from the Latin for “little frog,” based on the occurrence of many buttercups in moist habitats. The specific epithet is Latin for “clustered,” referring to the roots. In the U.S. the species occurs principally west of the Mississippi River in a broad band from Louisiana and east Texas northward to Minnesota, Wisconsin and Michigan; east of the Mississippi River, scattered occurrences are mapped from Mississippi and Georgia north to New York and New England. In Arkansas, Early Buttercup occurs statewide. Habitats vary from lightly shaded wooded bottomlands to sunny grasslands and even lawns, in moist or dry, loamy, sandy to rocky soils. It is also known as Thick-Root Buttercup.
Early Buttercup, one of 17 buttercup species in Arkansas, is the only species with tuberous roots. The low-growing plants have slender annual tubers (nutrient storage features) and white string-like (filiform) roots. In spring, new white tubers grow around the perimeter of the root crown as the previous year’s now-tan tubers, at the center of the root crown, soften and detach from the root crown. The cylindrical tubers are less than an inch long and ¼ inch wide. Tubers are arranged in a vertical position “hanging” below the round root crown. Plants may have only filiform roots.
Plants tend to occur in scattered seeded colonies with plant density seeming to be greater in more mesic, less sunny sites. Vegetative growth of plants consists of basal leaves and flowering stems, growing directly from the root crown. A cluster of one to several groups of in-facing leaves, on long slender petioles, surrounds one or two flowering stems.
A mature plant has simple, overwintering, 3-lobed basal leaves and, in late winter into spring, trifoliate compound basal leaves. Overwintering leaves, with blades to 3 inches long and 1 inch wide on a 2 inch petiole, have an obovate terminal lobe and a pair of smaller oblanceolate lateral lobes. Compound leaves have a terminal leaflet and a pair of lateral leaflets, the leaflets entire (uncut) or shallowly to deeply incised. Compound leaves have blades to 2 inches long and 1½ inches wide on a grooved petiole to 4 inches long with a clasping base. Basal leaves are reddish to green above and lighter green below; initially ascending, they become wide-spreading to reclined. Venation is obscure.
Early Buttercup is among the first of the Arkansas buttercups to produce flowers in the spring. First buds appear in mid-March, along with the trifoliate basal leaves. First blooms are positioned at center, close to the ground, as lateral stems develop. Each stem (or peduncle) bears 1-6 flowers, ascending to a length of 10 inches, and may have one to several axillary side stems. Although stems may recline to the ground, they do not root.
Flowers, in bloom for one day, are ½-1 inch wide with 5 sepals, 5 petals, and a ring of about 50 stamens surrounding about 40 pistils. In bud, the pale green sepals, which may have a persistent burgundy line along the central vein, form 5 prominent bulges. Boat-shaped, low-keeled sepals are wide at base and acute at the apex; they become light yellow with anthesis. Bright yellow petals, less than ½ inch long and ¼ inch wide (and about twice as long as the sepals), are broadest at about the middle with a rounded apex. Their upper surface is an overall glossy yellow, however the lower portion has a greenish tinge. Bright yellow stamens bear 2-lobed anthers, angled toward the flower center. The tightly packed pistils are glabrous with a short, sharply pointed beak (comprising style and stigma) also aligned toward the flower center.
Early Buttercup is noticeably pubescent. Plants typically have long straight hairs on stems, pedicels, peduncles, and sepals. The pubescence of petioles and lower stems is appressed. Leaf surfaces tend to be densely short-hairy, the hairs mostly appressed beneath. Pubescence decreases over the growing season. Petals and fruits are glabrous.
Following anthesis, petals and sepals drop off to expose a spherical head (less than 1/3 inch wide) of developing fruits. Fertilized flowers produce plump, somewhat flattened achenes, less than 1/8 inch wide, with a sharp angled beak (persistent style/stigma) to one side. Dry achenes may be dispersed by surface water flow and passing animals.
For garden use, Early Buttercup, with its overwintering basal leaves and new leaves and bright yellow flowers in late winter/early spring, would be a nice addition. However, in mesic shady habitats, it may form large colonies by self-seeding so that it may be better suited for wild gardens. Pollen and nectar attract various bees and flies. Seeds are eaten by game birds and small mammals.
Of the 16 other species of buttercups that occur in Arkansas (including 5 non-native species), all except one have glossy yellow flowers. Early Buttercup can be distinguished from most of the other species by noting differences in habitat, plant growth habit, and leaf shape. The plant most likely to be confused with Early Buttercup (especially during winter months) is Hispid Buttercup (Ranunculus hispidus var. hispidus). Early Buttercup can be distinguished from Hispid Buttercup based on: 1) tuberous roots, 2) spring-time leaves that are longer and more narrow, 3) earlier flowers, and 4) appressed hairs, especially along petioles and stems.
Article and photographs by ANPS member Sid Vogelpohl
Rue-Anemone (Thalictrum thalictroides; formerly Anemonella thalictroides) of the Buttercup (Ranunculaceae) family is a small, perennial, woodland ephemeral with an umbellate inflorescence of white to pink flowers. The genus name is the Latin form of the Greek word thaliktron, used in ancient times to describe some meadow-rues, possibly in reference to their compound leaves. The specific epithet, originally applied when the species was treated in the genus Anemonella, is a reference to the similarity of its compound leaves to those of the meadow-rues, plants already treated as species of Thalictrum. In the U.S., Rue-Anemone occurs from northeast Texas and southern Arkansas to Minnesota and east to the Atlantic Coast, reaching the Gulf Coast in Mississippi, Alabama, and the panhandle of Florida. In Arkansas, Rue-Anemone occurs across much of the state except for some portions of the Mississippi Alluvial Plain and low-lying areas of the West Gulf Coastal Plain. The common name “Rue-Anemone” is based on this species’ leaves being similar to those of the meadow-rues and its flowers being similar to those of the anemones. Other common names include Windflower based on the flowers’ quick response to breezes. Rue-Anemone is found in well drained, sandy to loamy, mesic soils within open deciduous woodlands and thickets and along woodland margins.
Rue-Anemone, an herbaceous perennial, occurs as isolated plants. The rootstock consists of a single tuber or 2-3 tubers joined at their tips. Depending on the time of the year, tubers may be globose or spindle shaped (fusiform). During the growing season, tubers shrink. When tubers become dormant in early summer, with nutrient reserves replenished, they are white and globose (see Photo 7). Whether a plant has one or several tubers, leaves and stems grow from a single near-surface caudex. Tubers are to 1½ inches long with long fibrous roots. Mature plants have one to several compound basal leaves and one to several floral stems. Stems and leaves grow directly from the caudex. The entire plant is glabrous (without hairs). Plants go dormant with the heat and dryness of summer.
Floral stems appear in late winter before the basal leaves. When stems first appear, flowers are hidden by a protective layer of leaf-like bracts. At full development, stems are 4-9 inches tall––an erect wiry leafless peduncle (or scape) topped with the inflorescence, surrounded by an involucral whorl of 3-9 bracts. The bracts, unlike the leaves, are simple, with a single rounded to obovate blade (see below) on a long wiry thread-like petiole. The inflorescence consists of a single flower (occasionally) or an umbel of 3-6 flowers (usually 3) on ascending thread-like pedicels to 1½ inches long. Umbels have a central larger flower which blooms before the laterals. Infrequently, a flower may have an “extra” subtending bract. Peduncles and pedicels are reddish in sunnier habitats, but trending to light green in more shaded habitats. Peduncles are typically three or more times longer than the pedicels.
Basal leaves are biternate (twice ternate) with three compound leaflets on a straight wiry petiole. Each compound leaflet has a terminal subleaflet and an opposite pair of lateral subleaflets. While leaves may be 3-10 inches long, a typical leaf is 3½ inches long and 2½ inches wide, including a 2-inch petiole, 1-inch petiolules (leaflet stalks), and ¼-inch subleaflet stalks. The glabrous leaves and bracts, all about the same size, are rounded to obovate, with rounded, indented base and a broad apex with 3 rounded shallow lobes. Blades, to about ¾ inch wide and broad, quake in the breeze. Venation is ternate, with primary veins terminating at the three main lobes. The upper leaf surface is medium green, the lower light green to purplish, especially along the veins. Blades of terminal leaflets and involucral bracts are similar in size and appearance.
Flowering may extend over the month of March and into April. Umbels, with 3-6 perfect (with stamens and pistils) flowers, have a central flower which blooms first and tends to be the largest flower of the umbel. Flowers, to 1 inch across (occasionally 1½ inches), have a showy calyx of 5-10 large petal-like sepals (true petals are absent), which may be pure white to pinkish (varying by plant), the pinkish flowers being an even darker pink in bud. Sepals are oblong to broadly lanceolate (with or without a tiny notch at the apex) and may be in a single or double layer. Flowers have numerous stamens with delicate, long, white filaments topped with bright yellow, 2-lobed anthers. Stamens surround up to 15 closely packed, postlike, stubby pistils, the green ovaries topped by short white styles and stigmas. Anthers are positioned above the stigmas, flowers above their leafy involucral bracts.
Fertilized ovaries produce ribbed seeds with a fusiform shape less than ¼ inch long, with a slightly skewed apex. A flower may bear up to 15 1-seeded fruits (achenes) which stand erect on a small spheroid base. Seeds, with 8-10 prominent longitudinal ribs, do not dehisce (split) when dry. At the end of the growing season (with hot or dry weather), with plants becoming dormant, tubers are white and globose.
For a garden or natural area, Rue-Anemone would be an excellent choice for a partially shaded flower bed or an open deciduous woodland. Although of small stature, flowers and leaves are decorative and interesting. Plants reliably produce blooms in late winter/early spring which provide pollen (no nectar) to early-season small bees and other insects. Flowering may persist for a month, the flowers remaining open during darkness and rainy periods. Rue-Anemone does self-seed well in favorable habitats, so that it is a good choice for a naturalized landscape. It is not eaten by deer.
Four additional species of the genus Thalictrum occur in Arkansas: Arkansas Meadow-Rue (T. arkansanum), Purple Meadow-Rue (T. dasycarpum), Early Meadow-Rue (T. dioicum), and Wax-Leaf Meadow-Rue (T. revolutum). Rue-Anemone may be distinguished from these four species by its small size, conspicuous petaloid sepals, leaf-like involucral bracts, ascending stamens, and umbellate inflorescences.
The Arkansas species most likely to be confused with Rue-Anemone is False Rue-Anemone (Enemion biternatum) which has similar size, leaves, and flower characters. However, False Rue-Anemone has several key differences: 1) Single flowers are axillary, 2) Flowers are always white and typically have five sepals, 3) Lobes of blade are incised, and 4) Fruits are dehiscent follicles rather than indehiscent achenes.
Article and photographs by ANPS member Sid Vogelpohl
Black Nightshade (Solanum ptychanthum) of the Nightshade Family (Solanaceae) is a common weedy native with small white flowers and black berries. The genus name, meaning “quieting,” is the classical Latin name for the nightshades, in reference to the narcotic properties of some species of the genus.* The specific epithet is formed from the Greek for “folded flower.” In the U.S., Black Nightshade is widespread, growing from south Texas to North Dakota, east to the Atlantic Coast. Occurrence in Arkansas is statewide. The species is also known as Eastern Black Nightshade and West Indian Nightshade. Habitats, often weedy, include sites with variously moist soils in full to partial sun, such as open woodlands, forest edges, thickets and croplands.
This annual or short-lived perennial species has a whitish, rather gnarled, branching taproot. Stems are erect when young but can become low-growing as they divide and lengthen. A mature plant, with several slender stems, may be only 6+ inches tall and 3 feet wide. Flowers are produced from June into October, with fruits until frost. Although plants have an overall leaf-and-stem pattern that is alternate, nodes may bear a whorl of one or two branches with or without leaves. Stems are medium green (aging gray-brown), glabrous or minutely pubescent (velutinous), and round in cross-section.
Leaves are simple, mostly alternate, petiolate, and broadly lanceolate to deltate, with acuminate, blunt tips and rounded to wedge-shaped (cuneate) bases. Petioles are partially winged by extensions of the leaf blade. Leaves, to 3 inches long (including petioles of ¾ inch) and 2 inches wide, are widest at and below the middle. Surfaces are medium green above and lighter beneath; like the stems, they are glabrous to minutely pubescent. Margins are entire to broadly undulate or bluntly dentate.
The inflorescence consists of small umbels growing directly from branches (not axillary or terminal). Peduncles (stalks of umbels) are ¾+ inch long and extend straight-out from the branch, while the pedicels, to 1/3 inch long, arch downward. Umbels have 2-6 (often 3) flowers. Peduncles and pedicels tend to be velutinous.
Flowers, ¼+ inch across, have a tight tubular calyx with 5 stubby triangular lobes and a sympetalous corolla of 5 narrowly triangular lobes. At anthesis, the star-shaped corolla of the pendant flower is strongly reflexed. Corolla lobes are a dull white overall, with shiny bright green flaring-out from the center. A central ring of five adnate, bright yellow, tubular anthers protrudes prominently from the corolla. The anther ring tightly encloses and hides the style, with only the small knob-like stigma exposed. Anthers have terminal pores for pollen release (poricidal dehiscence). When foraging bees settle on the flower, their buzzing vibrates the anthers, and pollen is released via the apical pores to be collected by the bees or become airborne. Pollen readily adheres to the sticky stigmas. Flowers do not produce nectar.
Fertilized flowers produce dangling spherical berries into late fall. A robust plant has the potential to produce 100+ berries. Berries, at first a mottled pale green, become solid black at maturity. The green star-like calyxes persist at the base of the shiny ¼-inch fruits. Berries contain to 75+ discoid tan seeds to 1/16 inch across in a gelatinous clear liquid.
For an informal garden or natural area, this annual prickle-free species may be appropriate. It grows well in a sunny to partially shady site. While plants may be aggressive, relatively large leaves, tiny flowers and black fruit do provide interest. Plants are classified as toxic to foraging animals, and green, immature berries contain solanine and should be avoided by people. Mature fruits and seeds are a food source for song and game birds and small mammals. Foliage is eaten by leaf beetles (Chrysomelidae family). Seed dispersal is by the bird and mammal foragers.
In addition to Black Nightshade, six additional species of Solanum occur in Arkansas. Black Nightshade is the only prickle-free species with small black fruits. One species, Carolina Horse Nettle, has been previously addressed in a “Know Your Natives” article.
*Plants in the Solanum genus (including tomatoes, potatoes and eggplants) contain solanine, a natural defense for the plants. Concentration of solanine varies by species and by plant part. Green fruit tends to have the greatest concentration.
Article and photographs by ANPS member Sid Vogelpohl
Carolina Horse Nettle (Solanum carolinense) of the Nightshade (Solanaceae) family is a toxic* perennial with attractive flowers and fruit and piercing prickles. The genus name is Latin for “quieting” in reference to the narcotic properties of some species. The specific epithet suggests that Linnaeus, who named the species, examined a specimen from the Carolinas, where the plant does indeed occur. Carolina Horse Nettle is found from east Texas north to Iowa and east to the Atlantic Coast from southern Maine to Florida. Additionally, there are scattered occurrences in some western states, likely as a result of introductions. In Arkansas, it grows statewide. Bull Nettle is another common name. Habitats include a wide range of soils in a wide variety of sites, from prairies to woodland margins, but this aggressive weedy native grows most vigorously in disturbed sandy to gravelly soils, including cultivated fields.
Carolina Horse Nettle, with taproots 5 feet or longer (!), and near-surface lateral roots, is an herbaceous perennial typically with tough, over-wintering dead stalks. The main stalk, 1-3 feet tall with alternate wide-spreading branches, bears scattered prickles (attached to the epidermis) as well as a more or less dense covering of stellate (star-shaped) hairs. The straight, rigid, yellowish prickles along stalk and branches, angling slightly downward, have widened bases and pin-like (sharp!) tips. Prickles are to ⅛+ inch long.
The alternate coarse leaves are oval to elliptic with a wedge-shaped (cuneate) base. They measure 2-4+ inches long, including a ½ inch petiole, and 1-3 inches wide. Smaller leaves tend to be unlobed; the larger blades have 2-4 prominent rounded-triangular lobes of varying size (largest at midleaf) and an elongate lobe-like apex. Margins are wavy and lipped (somewhat swollen). Surfaces are armed with scattered prickles on veins (mostly the midrib) and petiole. Sessile stellate pubescence, moderate above, denser beneath, does not obscure the green tissue. Venation is pinnate with the secondary veins terminating near lobe tips.
Flowers emerge from May to October in axillary and terminal clusters, with several to 20 flowers, the inflorescence elongating to a raceme as fruits develop. Rachises are free of prickles while peduncles may have scattered small prickles. Flowers bloom sequentially from the base of racemes as the rachis continues to lengthen and straighten. In bud, the inflorescence bears down-bent pedicels with dangling oblong buds. With anthesis, pedicels become ascending so that flowers face outward to upward. Lower portion of the rachis has sparse short hairs while pubescence of pedicels and calyx is more dense.
The perianth is pentamerous. The calyx tube bears 5 narrowly triangular lobes (¼ inch long), with a few small prickles. The white to lavender corolla, ¾-1 inch wide, bears 5 broad, delicate, pointed, widely spreading lobes about the same length as the tube. Five large anthers and a rather stout style project forward from the spreading corolla. The distal portion of the style protrudes just beyond the anther tips. The prominent, bright yellow, tubular anthers, on short white filaments, have a terminal pore for pollen dispersal (poricidal dehiscence). Flowers do not produce nectar. With the widespread corolla, bumblebees are able to easily settle across the anthers and stigma. When a bee vibrates its thoracic muscles (sonication), pollen loosens within the anther and exits via the apical pores. Airborne pollen or pollen attached to the ventral side of a bee adheres to the large sticky stigma.
Fertilized ovaries develop into smooth spherical fruits (berries), ½+ inch in diameter, without prickles or pubescence. Fruits, initially a shiny pale green, with slashes of dark green extending to mid-fruit from the pedicel, become a deep yellow at maturity. Over winter, leaves having fallen, the dangling yellow fruits and their calyxes persist on the dead stems. During the winter months, a fruit’s epidermis becomes tough and dimpled. A fruit may bear 80± yellowish slightly flattened oval seeds. Damaged fruits have a memorable, pungent scent.
For a garden, Carolina Horse Nettle would provide bold texture, and distinctive flowers and fruits. However, considering its piercing prickles and very deep taproots, a gardener would probably not want to introduce it. Once entrenched, it is difficult to control––cut roots propagate new plants. It has been listed as a noxious weed over most of its range due to its aggressiveness in disturbed sites. Plants are suitable for a natural area (woods or prairie) where shading and competing plants can restrict its spread. Being a native plant, it does provide sustenance to native insects, including bumblebees and tobacco hornworms (Manduca sexta), birds and small mammals.
Other plants in the genus Solanum which occur in Arkansas are Western Horse Nettle (Solanum dimidiatum), Silver Leaf Nightshade or White Horse Nettle (Solanum elaeagnifolium), Garden Tomato (Solanum lycopersicum), Black Nightshade (Solanum ptychanthum), Buffalo Bur (Solanum rostratum), and Hairy Nightshade (Solanum sarrachoides). Solanum dimidiatum is a more robust plant with larger leaves with 5 to 7 lobes and stalked stellate hairs, larger blue flowers (up to 2 inches wide) and larger fruit. Solanum elaeagnifolium is covered by densely matted short silvery pubescence and has entire or slightly wavy-margined leaves. Solanum lycopersicum is the non-native garden tomato, with the dissected leaves, glandular pubescence, and larger fruits (usually red-orange at maturity). Solanum ptychanthum is an annual species, without prickles, with no or few hairs (non-stellate), and with small flowers and black fruit. Solanum rostratum has deeply lobed leaves, yellow flowers, and prickly calyxes. Solanum sarrachoides, another non-native, is densely hairy with simple (non-stellate) glandular hairs and has small black fruit.
* Plants in the Solanum genus (including tomatoes, potatoes and eggplants) contain solanine, a natural defense toxic compound. Concentration of solanine varies by species and by plant part. For Carolina Horse Nettle, the greatest concentration is in the green fruit.
Saturday, May 1st, 1-2pm Benevolent Trees: Native Woody Plants in American Herbal Traditions with Steven Foster
Join Steven Foster on a photographic journey beyond mere plant identification to explore the remarkable human experience in interacting with woody plants for material and medicinal use, as well other ways of looking at our ligneous flora in both American history and contemporary experience.
Saturday, May 8th, 1-2pm Mosses: the Original Tree Huggers with Karen Willard
Mosses were one of the first plants to adapt to life on land, evolving from an ancient group of green algae around 450 million years ago. These plants are small and lack true vascular tissue, yet they have been able to colonize every ecosystem except for the ocean, living where most other plant groups can’t. In this program, Karen will explore some of the characteristics that make these plants unique, and will discuss their role in the biological community. The program will conclude with an overview of moss species common to Arkansas.
Wednesday, May 12th, 2-3pm Here Come the Invasivores! Foraging Invasive Species To Help Our Natives with Bo Brown
Join Bo Brown, author of Foraging the Ozarks, to learn about some of the tasty non-native and invasive plant species found in Arkansas. You’ll learn about methods of preparation, recipes, ethical collection, and ways to prevent the spread of these ecologically harmful species.
Thursday, May 13th, 1-2pm Who’s On Top: An Overview of theKnown Associations Between Plants and Fungi with Jay Justice
In this presentation, Jay will examine various types of mycorrhizal relationships, as well as other types of fungal-plant associations, including lichens, endophytic fungi, and myco-heterotrophic plants.
Saturday, May 15th, 2-3pm The Love Life of Ferns with Eric Sundell
The ferns are an ancient group of plants with a dominant presence in the fossils of the Coal Age, some 350 million years ago. And they remain, with their vascular tissues that transport water, minerals, and sugars, a prominent and competitive group in today’s modern flora. But unlike almost all of the modern plants we see around us, they have no seeds and no flowers. Instead, their life cycle is characterized by spores as well as by two quite different kinds of plants, one that produces those spores (and looks like a fern) and the other, the prothallus, a kind of alter-ego that looks like an alga or maybe a moss, that produces sperm that swim about on the forest floor hunting for eggs. We’ll take a look at the details of this bizarre and intriguing life cycle. We’ll also have a quick tour of Arkansas’ most common fernly beauties.
Saturday, May 22nd, 1-2pm Arkansas’s Grasslands: Natural History and Conservation with Theo Witsell
Synposis: Join Theo Witsell for a webinar on the grasslands of Arkansas, their natural history, and their conservation.
May 22nd, 3-4pm Ask the Experts! — Q&A Panel Discussion with Theo Witsell, Jennifer Ogle, and Eric Sundell
This is your chance to ask the experts questions you have about the native plants of Arkansas. Bring your questions to the live event, or submit them in advance to ANPS.President@gmail.com.
Lady Fern (Athyrium filix-femina*) of the Woodsiaceae (Lady Fern) family is a medium size fern of North America, Europe and Asia. The genus name originates from a Greek word referring to “door” in reference to the hinged indusia (protective spore covers). The specific epithet is based on Latin words for “fern” and “woman.” Lady Fern occurs across the U.S., including Alaska, as well as Canada. In Arkansas, Lady Fern is the only species of Athyrium and is found statewide. Preferred habitat is shady sites with moist to wet soils: rich woods, seeps, springs, moist areas of prairies, and at swamp and drainage borders. The common name relates to the graceful appearance of this “delicate” fern, as compared to “coarse” ferns, such as male fern (Dryopteris filix-mas).
Lady Fern is a hardy deciduous fern with shallow horizontal rhizomes to ¾ inch thick. Rhizomes produce new fronds (leaves) at their growing tips, with the bases of old fronds persisting for up to four years. Numerous wiry roots, with their lateral rootlets, grow from all sides of the rhizomes. Rhizomes of a mature plant occasionally divide, ramifying and rooting through the soil, to form a dense mat.
In early spring, tightly coiled fronds, pinnae (leaflets), and pinnules (secondary leaflets) emerge as “fiddleheads.” Protective papery elongate scales along the stipe (frond stalk), and the stipe itself, are reddish brown.
Ovate-elliptic fronds mature to 3 feet long and 10 inches wide; pinnae are narrower in shape and lanceolate-oblong. Fronds are light green above and below. Largest pinnae (5+ inches long and 1+ inches wide) are located near the middle of the rachis (pinna-bearing axis). Except for the two lowermost pinnae, which tend to be opposite, pinnae (20+ along both sides of rachis) are alternate. Size and separation of pinnae decrease distally, ultimately merging to form a fine-pointed apex. Fronds are mostly glabrous, except for the scales along the stipe, as noted above. The rachis is rounded on the lower side and flat with a central groove above. The stipe may be half as long as the rachis.
Lady Fern’s compound fronds are described as bipinnate to bipinnate-pinnatifid. The ultimate divisions, the pinnules, to ½ inch long and 3/16 inch wide, are sharply toothed with secondary veins terminating at the tips of the teeth.
Lady Fern has separate fertile and sterile fronds, with the same adaxial appearance. To find the fertile fronds, you turn them over to see the lower surface, which bears tiny clusters of spore-producing sporangia called sori (singular, sorus) or fruit-dots. Crescent- to oval-shaped sori are arranged in two rows on either side of the midrib of the larger pinnules. Early in development, the sori are partially covered by a translucent, hinged indusium. As spores develop, indusia dry and shift away to expose the sporangia and facilitate spore dispersal.
With dispersal of spores, the reproductive activity of the “sporophyte” phase of a fern’s life cycle concludes. In the soil, spores germinate to produce a prothallus, the “gametophyte” phase. The tiny prothallus produces gametes, sperm and egg. Sperm swim through ground moisture to fertilize eggs that have remained attached to the prothallus. Fertilization produces a zygote that, in turn, develops into a new sporophyte plant––the plant that we recognize as a “fern.”
For a shady to partially shady garden or natural area that has moist to wet soils, this delicate-cut fern should be considered. Plants have an airy appearance and provide nice contrast with coarse ferns and broad leaf plants. The weak fronds are easily damaged by wind and passing animals. Plants go dormant early with dry soil conditions. Lady Fern expands slowly by rhizome growth, but is not aggressive. For a similar appearing fern that is more compact, prefers drier soil, and tends to be evergreen, Marginal Wood Fern (Dryopteris marginalis), may be an alternative choice.
The ferns are an ancient group of plants with a dominant presence in the fossils of the Coal Age, some 350 million years ago. And they remain, with their vascular tissues that transport water, minerals, and sugars, a prominent and competitive group in today’s modern flora. But unlike almost all of the modern plants we see around us, they have no seeds and no flowers. Instead, their life cycle is characterized by spores and by two quite different kinds of plants, one that produces those spores and the other, the prothallus, that produces swimming sperm.
*Across its circumglobal range, Lady Fern has many variations. Two subspecies have been classified in the eastern U.S.: Southern Lady Fern (Athyrium filix-femina subsp. asplenioides) and Northern Lady Fern (Athyrium filix-femina subsp. angustum). These subspecies, which some authorities elevate to species, are distinguished by the location of the broadest widths of the fronds (closer to the base versus closer to the middle) and spore color, among other characters; however, variations do occur. The Arkansas subspecies is Southern Lady Fern, although the range of Northern Lady Fern approaches the state closely in Missouri and may occur within northern Arkansas.
Article and photographs by ANPS member Sid Vogelpohl
Canada rockcress (Borodinia canadensis*) of the Mustard (Brassicaceae/Cruciferae) family has small white flowers and long pendent bean-like fruits. The genus name most likely commemorates the Russian botanist Ivan Parfenievich Borodin (1847-1930) who founded the Russian Botanical Society. The specific epithet denotes the species’ occurrence in eastern Canada. In the U.S., it is found primarily from eastern Oklahoma and southern Minnesota, east to Massachusetts and the southern Appalachians. In Arkansas, Canada rockcress occurs primarily throughout the Interior Highlands. Habitat preference is dry to well drained, sandy to rocky soils of open areas. Other common names include sicklepod and sicklepod rockcress.
This biennial, developing from seed in late fall, forms an elongate taproot and a basal rosette of simple leaves over winter. The earliest basal leaves tend to be spatulate and petiolate while later basal leaves are mostly obovate and sessile. As the central stem develops, basal leaves may expand to 4 inches long and 1¼ inches wide. Early leaves are green to purplish above and dark purple beneath. Pinnate venation, though obscure, is somewhat enhanced by purplish coloration. Leaf margins have 6 to 8 prominent undulating pairs of teeth angled toward the apex as well as basal ear-like lobes on the lowermost blades. Basal leaves are covered with dense, white, straight or curved hairs.
A straight, erect, green to bluish central stem develops in spring as basal leaves drop away, growing to a height of 3 feet, including the terminal raceme. Robust stems may have a few lateral flower-bearing branches above. Stems have scattered straight or curved pubescence, more so near the base. Pubescence is lost as plants mature.
The alternate, simple, ascending to arching stem leaves are lanceolate to oblanceolate, sessile or short-petiolate near the base. Lower stem leaves are 4 inches long and 1 inch wide, the size decreasing upwards. Leaf pubescence is variable: lower leaves and lower leaf surfaces are hairier while more distal leaves and upper leaf surfaces may be glabrous. Venation of stem leaves is similar to that of basal leaves.
By mid-April, the growing stems are topped with a tight cluster of football-shaped flower buds covered with dense minute pubescence. As stems continue to elongate, the structure of the inflorescence becomes apparent: a bractless raceme, a hallmark of the mustard family. Primary racemes may bear 60+ flowers and grow to more than a foot long in fruit. On more robust plants, they may be branched. Flowers of a raceme bloom sequentially from base to apex. Pubescence is lost as fruiting progresses.
Flowers develop on down-curved, half-inch-long, minutely pubescent pedicels. Perianth parts are in fours: 4 sepals, 4 quarter-inch-long petals. The androecium comprises 6 stamens, 4 long and 2 short, another hallmark of the family. There is a single pistil. The narrow tips of the linear white petals (about 3/16 inch long) extend just beyond the sepals and become widely spread to expose the anthers. The elongate, 2-carpellate pistil, with its minute style, remains mostly hidden.
Fertilized flowers, the sepals shed, produce long, slender, glabrous, 2-valved, bean-like fruits (siliques) that become prominently curved with maturity. Mature siliques, to 4 inches long and ⅛ inch wide, are of uniform width and thickness. They become tangled with one another as they elongate. When fruits are mature, the valves break apart and seeds are shed. Dead plants with their prominent seedless fruits become a light tan in color.
Structure of the ovary and fruit of the mustard family is unique. The partition separating the valves is not a seed-bearing placenta––seeds are attached not to the partition itself (this would be axile placentation) but to the junction of the partition with the valve, creating parietal placentation. (The partition is often termed a false septum or replum.) There are thus 4 lines of ovules in the ovary and 4 lines of seeds in the mature siliques. This becomes evident when the siliques dehisce along the junction of the valves: valves fall away while the replum, with seeds still attached on both sides of its edges, remains on the receptacle. The flattened round to oval seeds separate one from another with each seed retaining a “halo” of the translucent replum. Seeds are dispersed by wind.
With its height and distinctive racemes, Canada rockcress adds textural variety to a garden (see Photo 6). Nectar and pollen are beneficial to small flies and bees. At the end of the growing season, plants quickly disintegrate. It is apparently not an aggressive self-seeder.
Three other species of the genus Borodinia occur in Arkansas: smooth rockcress (Borodinia laevigata), Missouri rockcress (Borodinia missouriensis), and Short’s rockcress (Borodinia dentata). Canada rockcress can be distinguished by its 1) pubescent basal leaves with prominent teeth (but not significantly lobed), 2) non-clasping, tapered to the base, mostly sessile stem leaves, and 3) down-curved pedicels bearing pendent flowers and wider long curved fruits.
*Formerly classified as Boechera canadensis and Arabis canadensis. More recently, based on DNA testing, Canada rockcress and other Boechera species in Arkansas have been transferred to form a clade with Borodinia macrophylla, an Asian species.
Article and photographs by ANPS member Sid Vogelpohl