Arkansas Native Plant Society

Know Your Natives – Winged Sumac

Posted on November 21, 2021 by ANPS Webmaster

Winged Sumac (Rhus copallinum*) of the Cashew (Anacardiaceae) family is a deciduous shrub or small tree that forms clonal colonies from lateral roots. Rhus is the old Greek and Latin name for sumac. The specific epithet, based on an Aztec word, translates as “resinous,” in reference to its sap, or copal, a name given to tree resin. This is a common species throughout much of the U.S., from central Texas, southeastern Nebraska, and central Wisconsin eastward. Alternate common names include Shining Sumac, Dwarf Sumac and Flame-Leaf Sumac. Habitat ranges from full to partial sun on various soils––sandy to rocky, dry to mesic––on prairies, woodland edges, fencerows, roadsides, burned areas, and abandoned fields. Winged Sumac is an early successional species and is considered to be invasive in managed, tall-grass prairies.

**Photo 1:** This clonal colony, in a prairie-like setting, is in an area subject to controlled burns. Photo – October 30.

The parent tree of a clonal colony has a taproot with shallow lateral roots that may extend for many feet. Clonal trees, or root sprouts, grow from adventitious buds along the upper side of the lateral roots. Vegetative clones may occur as thickets or as widely scattered trees. Lateral roots remain viable throughout the short lifetime (less than 20 years) of a clonal colony. Roots that are slightly cut or flexed slowly exude a small quantity of white, resinous sap. Wood of the stems is white, surrounding a tan pith.

**Photo 2:** This parent tree (3½ feet tall) has a stubby taproot and four lateral roots, one of which was uncovered for 14 feet, but extended farther. Lowermost point of this taproot was dead, suggesting that the taproot of parent plants becomes insignificant with development of lateral roots.

**Photo 3:** Lateral roots are variable in diameter. Arrows indicate stems of clonal trees or root sprouts. Sprouts do not develop taproots. Note that fibrous roots occur along the main lateral root and on dead-end branches.

**Photo 4:** This trunk segment (above) and lateral root segment (below) were taken from the tree shown in Photo 2. White resinous sap exudes from injuries on the trunk and root. Trunk and root are roughened by numerous lenticels.

**Photo 5:** Mature trunks (of trees in Photo 6) are roughened by a concentration of lenticels and slightly exfoliating bark. Circumference of tree on right is 17½ inches. Photo – November 8.

Stems (trunks) of clonal trees in their first one to two years of growth are straight and unbranched, elongating from the terminal bud only. By the third year, lateral stems (branches) grow from one to several of the uppermost axillary buds. When a clonal tree is mature enough (fourth year?) to produce an inflorescence (always terminal), lateral buds immediately below the inflorescence produce new branches. Growth rate of stems varies widely, from less than an inch to several feet, as determined by specific site conditions (soils, moisture, shading) and the age of the clonal tree. Mature trees in an open space have a broad, rounded top, while crowded trees are slender with lower branches lost due to shading. Trees typically reach a height of 10 to 12 feet, but may reach 30+ feet. Entire clonal colonies die when shaded by a closing forest canopy.

**Photo 6:** These several tall ( 36+ feet) Winged Sumacs, at center of photo, are part of a larger clonal colony and are now struggling to survive in a closing forest canopy. Photo – November 8.

New, pale green stems are densely covered with velvety white hairs (puberulent) that extend onto the petioles (leaf stalks). This pubescence persists as stems age and darken. Small dark lenticels (air pores) on current-year’s stems become more numerous from year-to-year, giving the thin, gray to reddish bark of larger trees a rough, pustulate appearance. Trunks often have a few large white splotches.

**Photo 7:** New stems grow from axillary buds immediately below last year’s fruit cluster. Remnants of a two-year-old infructescence can be seen at lower right. Photo – April 14.

The alternate, odd-pinnately compound leaves bear 5-25 leaflets. Leaves grow to 12 inches long (including a 2½ inch petiole) and 2 inches wide. Petioles may be reddish. Sessile to sub-sessile leaflets, to 3½ inches long and 1½ inches wide, are lanceolate to ovate-lanceolate, with a rounded to attenuate base and acute or acuminate tip. Leaflets can be asymmetric across the midrib with the upper half wider. Margins are typically entire (smooth), though slight serrations may occur distally. The leaf rachis––the midrib between the paired leaflets––is prominently winged, the wings from ⅛ to ⅜ inch wide. A stubby wing also occurs at the base of the terminal leaflet. Leaflets and wings are dark, shiny green above and dull, yellowish green beneath. Upper leaf surface is mostly glabrous, the lower surface densely pubescent with short spreading hairs. At the end of the growing season, small axillary buds for next year’s new lateral branches are somewhat obscured by slightly elevated, crescent-moon-shaped leaf scars.

**Photo 8:** The odd-pinnately compound leaves have a dark shiny green upper surface and a dull yellowish green lower surface. Leaf at left is 11¾ inches long and 7 inches wide. Photo October – 12.

**Photo 9:** While upper leaf surfaces are generally glabrous, lower surfaces are densely pubescent. Length of wing at center of photo is 1¼ inch. Photo – November 5.

In June and into July, terminal buds produce large, upright, conic, densely pubescent, branching panicles. Flowers are closely packed. Yellowish green corollas, ⅛ to 3/16 inch across, are set in a dark green, bowl-shaped calyx with 5 triangular lobes.

Winged Sumac is a dioecious species––unisexual flowers (pistillate or female flowers and staminate or male flowers)––occur on separate plants as well as on separate clonal colonies. In the case of a fully dioecious species, pistillate flowers lack stamens and staminate flowers lack pistils. However, with Winged Sumac, pistillate flowers may have rudimentary (infertile) stamens and staminate flowers may have rudimentary pistils. The female flowers have 3 stocky, spreading styles with round stigmas atop a pubescent ovary with a single ovule. The male flowers have 5 stamens that extend well above the corolla so that the relatively large, lobed, light yellow anthers are well exposed. Pollen is dark yellow.

**Photo 10:** This compound panicle bears pistillate flowers. The infructescence from the previous growth-year remains, the fruits uneaten. Note that the reddish stems and petioles remain pubescent. Photo – June 20.

**Photo 11:** These pistillate flowers have 3 styles and 5 infertile stamens. Pubescent ovaries of two flowers at upper right can be seen. Lobes of a dark green calyx can be seen at right center. Photo – June 20.

**Photo 12:** This compound panicle bears staminate flowers. Viewed from a distance, such panicles appear to be yellowish. Photo – June 20.

**Photo 13:** Staminate flowers have 5 slender stamens topped with prominent, ribbed anthers. Flower at upper left has an infertile pistil. Pollen is yellow. Photo – June 20.

Female trees may produce large quantities of fruit on eventually drooping panicles. Clusters, 6+ inches long, persist into the following spring and remnants may persist into the second spring. The ovoid drupes, to 3/16 inch long, are reddish purple at maturity in mid-August and become brown and black as they shrivel over winter. Fresh drupes are covered with dense spiky white hairs. Tan smooth stones (to ⅛ inch across) have a flattened pea shape.

**Photo 14:** This tree has especially long stem segments and many large clusters of fruits. Trees at lower right and leaves at upper left are Serviceberry. Photo – October 12.

**Photo 15:** For this display, small lateral clusters were pulled down to loosen up the tight compound panicle. Photo – October 17.

**Photo 16:** Densely pubescent fruits are red to reddish purple at maturity. Uppermost fruit is 3/16 inch across. Stones are ⅛ inch across. Photo – October 17.

In considering Winged Sumac for a garden, there are a number of characters to recommend it: 1) an easily grown small tree with attractive green leaves, 2) copious showy panicles of tiny flowers that benefit insects, 3) fruits that are an important source of food for many birds and small mammals, and 4) excellent fall color. With pruning of lateral roots to remove excess root sprouts, a desirable ornamental plant may develop. Without root pruning, Winged Sumac is excellent for naturalizing larger areas and for erosion control on slopes. It may adapt to a container.

Four additional species or varieties of Rhus occur in Arkansas: 1) Fragrant Sumac (Rhus aromatica var. aromatica), 2) Tall or Midwestern Fragrant Sumac (Rhus aromatica var. serotina), 3) Smooth Sumac (Rhus glabra), and 4) Skunk-Bush Sumac (Rhus trilobata var. trilobata) (Little River County only). Only Smooth Sumac has similar leaves, inflorescence, and fruit. It can be distinguished by: 1) lack of wings along the leaf rachis, 2) fully serrated leaflets, and 3) upright mature fruited panicles.

**Photo 17:** Winged Sumac (left) and Smooth Sumac (right) both have excellent fall color. These trees re-grew after being cut and are thus more shrub-like. Photo – November 7.

*Some authorities have identified two varieties of Winged Sumac: 1) Eastern Winged Sumac (Rhus copallinum var. copallinum) which has 11-25 leaflets with attenuate bases and entire margins and 2) Western Winged Sumac (Rhus copallinum var. latifolia) which has 5-13 leaflets with rounded bases and margins that may be entire or serrate in their upper portion. The distribution of these varieties in Arkansas has not been well-mapped.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Shrubs, Trees, Wildflowers | Tagged Anacardiaceae, Know Your Natives, Rhus, Rhus copallinum, Sumac | Leave a comment

Know Your Natives – Carolina Buckthorn

Posted on November 8, 2021 by ANPS Webmaster

Carolina Buckthorn (Frangula caroliniana, formerly Rhamnus caroliniana) of the Buckthorn (Rhamnaceae) family is an elegant, thornless (!), deciduous shrub or small tree, with simple shining leaves and red to black berry-like fruits. (The tiny, whitish flowers are easily overlooked.) The genus name originates from the word “frangible” meaning “easily broken.” The specific epithet recognizes that the species was first described from specimens collected in the Carolinas. It occurs primarily from central Texas to central Missouri, east to Virginia and central Florida. In Arkansas, plants are found statewide except for portions of the Mississippi Alluvial Plain. Habitats vary, with soils acid to limy, moist to dry, in sun to part shade, in woodland margins, glades, bottomlands and stream terraces. The species is also known as Indian-Cherry.

**Photo 1:** Lower portion of this tree, positioned at a woodland edge, is compact and leafy as compared to the more sparse upper portion that extends into the overstory. Top of tree indicated by arrow. Photo – July 21.

**Photo 2:** This understory tree, located among large canopy trees of other species, has an estimated height of 36 feet and a spread of 19 feet. Dead limb on right is 6 feet above the ground. Photo – October 21.

Carolina Buckthorn is typically 10 to 15 feet tall, but may reach 30+ feet, especially on partially shaded sites. On sunny sites, plants develop a denser limb structure and often become rather shrubby. Despite the common name, none of the “Buckthorns” segregated from Rhamnus into the genus Frangula are armed with thorns. In addition, Frangula species are characterized by naked winter buds, that is, buds composed of tightly folded miniature leaves that are not protected by scales––a distinctive character useful for winter identification. Young branches have dense, minute, appressed pubescence (extending onto leaf petioles) that is lost by mid-growing-season. Twig color changes from pale green to tan and ultimately to gray as branches mature. Bark is thin and smooth with slightly raised whitish lenticels and leaf scars as well as whitish splotches and short tight fissures.

,**Photo 3:** The root of this 5-foot tree suggests that the roots of larger trees would be similar, that is, with major roots extending laterally as well as descending to depth.

**Photo 4:** A display to show changes of color and texture as branches and trunks mature. Diameter of trunk at left (same plant as shown in Photo 3) is ⅝ inch. Branch at far right is current year’s growth with leaves removed. Leaf at right is 6 1/4 inches long and 2 1/4 inches wide. Photo – October 17.

**Photo 5:** This trunk of a 36-foot tree (also shown in Photo 2) is mostly smooth with whitish splotches and slight fissuring. The trunk has a circumference of 15¾ inches at 5 inches above ground.

**Photo 6:** Terminal and lateral buds are composed of pubescent miniature leaves which are not protected by scales. With leaves removed, the three vascular bundles can be seen in the leaf scar. Photo – October 6.

Alternate elliptic to obovate-elliptic leaves, with a shiny dark green upper surface and a dull pale green lower surface, have a rounded to cuneate base and an apex that may be acuminate, acute or obtuse. A large leaf may be 6½ inches long, including a ⅝-inch petiole, and 2 inches wide, the largest leaves occurring toward the branch tips. Venation is offset-pinnate, with 8-10 pairs of prominently straight and parallel secondary veins that bend forward near the leaf margin. Margins are irregularly and obscurely crenate. Persistent dense minute pubescence of the petiole extends onto the veins of the blade beneath, with longer scattered hairs between the veins. Upper surface of the leaves feels smooth; lower surface feels corrugated, due to expressed lateral veins. Leaves droop in dry spells, but quickly rebound with renewed moisture. Leaves become yellow to bronze in fall.

**Photo 7:** The simple, elliptic to obovate-elliptic leaves are shiny dark green above and dull pale green beneath. They have equally spaced, perfectly parallel secondary veins that extend toward the leaf margin. Photo -May 28.

**Photo 8:** Secondary veins extend to near the leaf margin where they align with the margin and interconnect. Margins are minutely irregularly notched. Upper surface shown on left and lower surface on right. Photo – October 17.

The inflorescence, from May into June, consists of axillary umbels of tiny (⅛ inch wide and long), pale green to whitish flowers on short, ascending pedicels. A peduncle may support 1-10 flowers. Peduncles, pedicels, and calyxes are densely puberulent.

**Photo 9:** Umbels of 10± flowers are axillary to current-year’s leaves. Naked buds for the next year’s growth can already be seen at top of photo. Leaves are alternate or rarely subopposite. Photo – June 3.

The inconspicuous, perfect (with male and female structures) flowers have a small, campanulate (bell-shaped) hypanthium, bearing 5 triangular sepals, 5 petals, and 5 stamens. Petals are smaller than sepals, and the stamens are positioned opposite the petals––a very unusual morphology. The compound pistil in center bears an undivided style with sunken stigmas. Flowers in bud form a 5-sided pyramid and, in bloom, spread wide to form a star. When lobes of the perianth open, the petals are wrapped around the stamens. With the petals unfurled, the pale yellowish-green, strongly ribbed anthers are exposed.

**Photo 10:** Two small umbels are shown on left and a larger umbel on right. Puberulent peduncles and pedicels are straight and stout. Exterior surface of hypanthium and lobes are similarly pubescent. Photo – May 28.

**Photo 11:** Inconspicuous petals initially shroud the stamens (see open flowers on left and right). Several flowers have progressed to early fruits. Dense minute pubescence of the petioles can be seen. Photo – May 28.

**Photo 12:** Petals and stamens are positioned between calyx lobes. Three fused carpels of the pistil form a central column topped with three round, sunken stigmas (flower at upper right). Photo – June 28.

Trees in favorable sites can produce a copious quantity of fruits (drupes). The spherical, ⅜-inch drupes change from green in July, to red in August, and black in October. The black mature drupes have a tiny stubby point at their apex (scar of style). The thin-skinned mature drupes contain three relatively large stones (¼ inch x ⅜ inch) that are pressed together in a white, rather pungent flesh. The black skin of fruits may cause the flesh of a crushed fruit to be purplish The dark brown stones, with tan bases, have a rounded side and two flattened sides with a slight rib separating the flat sides. Fruits, supported by stout peduncles and pedicels, tend to be readily visible between leaves.

**Photo 13:** Initially green, fruits are axillary on current-year’s growth. Leaves tend to be larger at and near the ends of branches. Photo – July 21.

**Photo 14:** Fruits transition from green to red in late summer. Shiny leaves have prominent, equally spaced pinnate venation. Photo – August 23.

**Photo 15:** Fruits transition from red to black at maturity in the fall. Leaves become yellow or sometimes bronze in fall. Photo – September 21.

**Photo 16:** The black fruits each contain three stones which are pressed together (shown at right) so that each stone has a rounded side and two flattened sides. Squares = ¼ inch. Photo – October 6.

Carolina Buckthorn may be an excellent choice for a partially sunny garden border or natural area. With its glossy green leaves and its red to black fruits, it is showy over the entire growing season. Leaves tend to be retained during dry periods, and, though becoming limp, quickly respond to wetter conditions. Rate of growth, size and form vary considerably depending on a tree’s number of sun-hours. Plants in full sun tend to be more densely branched and produce a larger quantity of fruits. Carolina Buckthorn is fairly aggressive at self-seeding so that seedlings may need to be controlled. When other choices diminish, fruits are appreciated by many birds and small and large mammals.

Carolina Buckthorn is the only species of the genus Frangula that occurs in Arkansas. A native species of the same family and somewhat similar character is Lance-Leaf Buckthorn (Rhamnus lanceolata) which occurs in the Ozark Mountains in the northern two tiers of counties in Arkansas. Lance-Leaf Buckthorn is a shrub to 9 feet tall, with smaller and usually more lanceolate leaves, smaller glabrous clusters of 4-petaled, separate staminate and pistillate flowers, and buds with scales. Two non-native species of the genus Rhamnus have been reported escaping at a few sites in the Ozark Mountains, namely European Buckthorn (Rhamnus cathartica) and Dahurian Buckthorn (Rhamnus davurica). These non-native trees have mostly opposite and more rounded leaves; short, thorn-tipped twigs and larger branches; and fruits each with either 3-4 stones (European Buckthorn) or 2 stones (Dahurian Buckthorn).

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Shrubs, Trees | Tagged Buckthorn, Carolina Buckthorn, Frangula, Frangula caroliniana, Know Your Natives, Rhamnaceae | Leave a comment

Know Your Natives – Hairy Bush Clover

Posted on October 22, 2021 by ANPS Webmaster

Hairy Bush Clover (Lespedeza hirta) of the Pea or Legume (Fabaceae) family is a perennial herb with stems to 3+ feet tall, bearing tightly clustered racemes of small creamy white flowers. The genus name is dedicated to Vicente Manuel de Cespedes (an early botanical text misspelled his name as “de Lespedez”), governor of the Spanish province of East Florida, 1784-1790, during the botanical travels there of Andre Michaux who described the genus. The species name is from the Latin word hirtus for “hairy,” in reference to the plant’s dense pubescence. In the U.S., the species occurs across a large area from eastern Texas and southern Michigan, east to Maine and Florida. In Arkansas, it occurs mostly statewide with the exception for portions of the Mississippi Alluvial Plain. Habitats are sunny to partially sunny areas in sandy to rocky, dry to moist soils, such as open woodlands, prairies, and glades.

**Photo 1:** Growing in full sun on a steep rocky slope, this plant is especially bushy due to early stems having been browsed by deer. Photo – October 5.

Plants produce several to many slender, round stems from a relatively short taproot and wide-spreading lateral roots. Stems average about 3 feet long but may reach 4½ feet. A 4-foot plant may have stems ¼ inch thick near the base. Smaller plants tend to branch only in the inflorescence, while more robust plants may have branches from mid-stem to 16 inches long with secondary branches of several inches. In general, lower branches are shorter than upper branches. Most branches terminate with an inflorescence. Stems are erect but become broadly arched as height increases and with the weight of the inflorescence. Stems and branches are uniformly covered by dense, short, soft, spreading pubescence. Stems are brittle and snap easily.

**Photo 2:** This plant, with six living stems to 3½ feet long, has a central taproot (see red arrow) and several widely spreading near-surface lateral roots. Bases of current-year stems bear buds for next year’s growth. Width of the root system shown in photo is 8 inches. Photo – October 10.

**Photo 3:** Spring growth is from the living base of previous year’s persistent dead stems. At this stage and throughout the growth cycle, dense pubescence covers the plant. Photo – March 29.

Compound, trifoliate, alternate leaves are regularly spaced from the base of the stem into the inflorescence. Both lateral and terminal leaflets are ovate to orbicular, green above, pale and yellowish beneath, with apexes and bases equally rounded. Leaves may be as large as 2+ inches long, including a ½-inch petiole, and 2 inches wide. The tip of the leaflets is typically mucronate––bearing a minute spine-like extension of the midrib. Like the stems and branches, the petioles, petiolules (leaflet stalks), rachises, and the undersurface of the leaflets are pubescent with rather softly spreading hairs. Pubescence of the upper leaflet surface is sparser and more appressed. Leaf bases bear a pair of weak greenish spine-like stipules (to ⅛ inch long) which quickly become brown but often remain attached. Venation is pinnate with upper veins weakly recessed and lower veins strongly expressed. Leaflet margins are entire (uncut) and strongly revolute (down-turned). With stem age and drying soils, leaf-drop proceeds upwards from the stem base and may extend into the inflorescence

Bloom time is September into October. The inflorescence comprises short (to ¾ inch), dense racemes of small, short-stalked flowers at the tips of the stems and branches. Racemes that are lower on the plant are subtended by a leaf, while those above are subtended by a pair of tiny broadly triangular bracts. Racemes may be sessile or on straight peduncles to 1½ inches long. They bear up to about 20 flowers. Often, especially at the top of the plant, racemes become densely spaced, terminating the stems in tight clusters of 15± racemes. Drying soil causes some racemes to not develop fully, resulting in naked peduncles during the growing season.

**Photo 4:** The trifoliate leaves bear ovate to orbicular leaflets. Relative length of petioles and rachises is variable––on leaves shown, they are about equal. Leaflets may have tiny apical mucros.

**Photo 5:** Leaflets have entire (uncut) revolute margins and pinnate venation. As shown, several peduncles did not develop or retain flowers, due to drying soil. With this reclined pair of branches, leaves and inflorescences have re-oriented toward the sun.

**Photo 6:** These racemes, oriented toward the sun, are at the early stage of blooming. Flowering has begun as racemes continue to lengthen, and developing flower buds become increasingly pointed.

Flowers have a bilaterally symmetrical, pea-like structure typical of the majority of genera in the Legume family: an upright broad banner petal, a pair or elongate wing petals, and a pair of keel petals fused together along their lower margins to form a boat-shaped keel. Wing and keel petals together form a central enclosure that conceals the pistil (ovary + style + stigma) and stamens (filaments + anthers). The corolla is creamy white, the banner with two sets of purplish red “pollinator guides” that radiate from just above the pale green throat and a central crease that extends out of the throat to a slight apical point. The small flowers are ¼ inch long and, when viewed from the front, 3/16 inch tall and ⅛ inch wide. The calyx, 3/16 inch long, has 5 narrow-elongate, sharply pointed, triangular lobes. Calyx lobes, fused at their lower third, are positioned with an upper pair behind the banner, a pair to the sides, and a single lobe directly below the keel. All lobes are pressed against the corolla. The calyx is densely covered with long hairs. Of the 10 slender staminal filaments, 9 are fused in their lower half and tightly encircle the pistil, forming a sort of “column.” The tenth free-standing stamen is positioned between the pistil and banner. Flattened globular anthers, at the apex of the greenish-white filaments, are yellow with a surface that is irregular with intertwined ridges. The ovary bears a short greenish white slender style tipped with a small circular stigma. Towards the distal end of the stamen-pistil column, the column arches upward so that anthers and stigma are positioned just inside a slit at the tip of the keel.

**Photo 7:** The small flowers, with stubby pedicels, are creamy white with purplish red pollinator guides across the broad banner. Appressed pubescence on upper leaf surface (at lower left) may be seen as a sheen. Photo – September 15.

**Photo 8:** Dense pubescence extends from stems onto peduncles (a segment shown at lower right), pedicels and calyxes. (Two racemes are shown, their apexes to left.)

**Photo 9:** While racemes lower in the inflorescence are subtended by leaves, closely spaced upper racemes are subtended by pairs of broad short bracts and the flowers are subtended by a pair of elongate bracts. As shown, the short and elongate bracts are brown.

**Photo 10:** Note 1) size of calyx relative to corolla, 2) arrangement of the 5 calyx lobes on right flower, 3) pair of bracts at base of calyx on left flower, and 4) relative size, shape, and orientation of wing and keel petals––wing petals spread (left) as flower develops.

**Photo 11:** In main photo, wing and keel petals have been spread to expose the stamen/pistil column (with 9 fused stamens). Inset shows the single free-standing stamen (diverted down from the column from its natural position projecting forward with the other stamens) and the clawed wing and keel petals (shown combined).

Fertilized flowers produce thin, flat, oval pods or legumes with an extended, sharply tapered beak (remnant of the style). Pods are densely pubescent. With fruit maturity, calyxes and pods become the same rich brown color. Pods extend beyond calyx lobes. Each dry pod contains a single dark brown seed <⅛ inch long with a somewhat flattened oval shape and smoothly rounded edges. Dried calyxes persist into winter.

**Photo 12:** Pods partially extend out of the calyx (red arrow). Cluster at upper right is composed of four or more racemes. Photo – October 4.

**Photo 13:** Pods and calyxes dry simultaneously. Pods with calyxes are at upper center, separated pods are on right, empty calyxes on left, and seeds at lower center. Photo November 30.

With regard to gardening, Hairy Bush Clover has an ungainly structure, non-showy leaves and flowers, and is not especially noticeable in winter months. Thus, it may be ideal only for a Wild Garden or Natural Area. Propagating by seed only, it is not an aggressive spreader. Branching can be encouraged by removal of stem tips at mid-season. Foliage is eaten by caterpillars of several Skipper species and the Io Moth. Seeds are eaten by birds and small mammals.

**Photo 14:** A volunteer plant in this Wild Garden has a dozen or so current-year stems, along with several dead stems that persist from the previous year. Plant at lower left is Arkansas Yucca. Photo – June 2.

**Photo 15:** Hairy Bush Clover is one of a number of plant species that hosts the Io Moth (*Automeris io*) caterpillar, noted for its sharp stinging hairs. Photo – September 20.

Frost flowers were seen on a dozen Hairy Bush Clover plants on January 3, 2022 in Logan County.
Temperature on that date was 23 degrees after an extended period of 70-degree weather and, two days
before, 3 inches of rain. Occurrence of Frost flowers on Hairy Bush Clover is unusual. One report can be found at the Biodiversity Heritage Library (biodiversitylibrary.org). For information on Frost Flowers, see “Frostweeds ‘Bloom’ Frost Flowers”.

**Photo 16:** Frost flowers on Hairy Bush Clover are unusual; requiring specific weather
conditions. Photo – January 3, 2022.

In Arkansas, 7 additional native species and 3 non-native species of bush clovers (Lespedeza) occur. Two of these are ground-hugging trailing plants and most of them have pink to lavender flowers. The one most similar to Hairy Bush Clover is Round Head Bush Clover (Lespedeza capitata). Round Head Bush Clover has similar structure and flower color, but its leaflets are linear-oblong, its inflorescence stalks are shorter than the leaf petioles, and its pubescence usually gives the plant a distinctly silvery appearance.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, White, Wildflowers | Tagged Fabaceae, Hairy Bush Clover, Know Your Natives, Lespedeza, Lespedeza hirta | Leave a comment

Know Your Natives – Fragrant Sumac

Posted on October 11, 2021 by ANPS Webmaster

Fragrant Sumac (Rhus aromatica var. aromatica) of the Sumac (Anacardiaceae) family is a dioecious, low-growing, non-suckering, non-poisonous shrub with tiny yellow flowers that emerge before the leaves. The genus name Rhus is the old Greek and Latin name for sumac. The specific epithet is Latin for “aromatic” or “fragrant,” describing the strong and pleasant scent of the crushed leaves. In the U.S., Fragrant Sumac, at the broader species level, occurs across most of the country, but is generally absent from the Pacific Northwest, upper Midwest, Maine, and the Coastal Southeast. In Arkansas, the species occurs statewide except for portions of the Mississippi Alluvial Plain. Habitats are widely varied, the plants occurring on practically any soil type, dry to moist, with a preference for dry, sunny to partially shaded, rocky sites, such as woodland margins, prairie slopes, and rights-of-way.

Young plants have erect wiry stems, but in subsequent years, stems often become ground-hugging and wide-spreading. Those in contact with soil are anchored by shallow, fibrous roots, as well as by longer and deeper roots. Stems and their branches may be 12+ feet long with each stem having 1-4 ascending, smooth, brownish red branches that may be 3-5 feet long. Older stems become dull brown and roughened by elongate corky lenticels (air pores). A mature plant may have a dozen or more radiating main stems and hundreds of branches that form a dense thicket, especially when mixed with other shrubs and vines. When a larger stem is cut through, it visibly extrudes a sticky sap, containing concentrated tannin.

**Photo 1:** This 2-3-year-old erect plant is 12 inches tall. Photo – April 19.

**Photo 2:** Main photo (litter removed) shows “point of origin” for the stems of a plant that extend outward to 13 feet. Inset photo (soil and litter removed) shows roots and stems at the central rootstock of a smaller plant. Stems bear lenticels and roots have circular growth scars. Photos – September.

**Photo 3:** This plant is in a sunny rocky area has relatively short ascending branches and exhibits leaf loss due to drying conditions. Photo – August 1.

**Photo 4:** Display shows three stem segments at left and two branch segments at right. Branch segments, with leaves removed, grew in the current growth-year. Large stem is 5/8 inch wide at base. Photo – September 26.

The cone-like inflorescence appears in mid-summer at the ends of the current year’s floral twigs in axils of the uppermost leaves. The following spring (mid-March), twigs bear flowers and (in female or pistillate plants) immature fruits as the leaf-bearing branches appear. New branches are initially bright green (in mid-April) and elongate to a few inches or to as much as 3 feet. New leaves are puberulent on the upper surface, with longer hairs along the veins below––all lost by mid-summer. Floral twigs die by mid- to late summer, after fruits mature.

**Photo 5:** Current-year branches develop from axillary buds immediately below the floral/fruiting twigs. As seen, current year’s fruits are mature as next year’s floral twigs, with their cone-like inflorescences, are already present at branch apex. (Also see new branches in Photo 11) Photo – July 31.

Alternate trifoliate leaves, with a terminal leaflet and an opposite pair of smaller lateral leaflets, expand to 5 inches long (including a slender petiole to 1½ inches) and 4½ inches wide. Terminal leaflets tend to be obovate, lateral leaflets oval to elliptic and asymmetric. The terminal leaflet is strongly attenuate or wedge-shaped at the base and sessile to sub-sessile at its junction with the lateral leaf pair––a character that quickly separates Fragrant Sumac from look-alike Poison-Ivy and Poison Oak. Leaflet margins above the middle are coarsely toothed (crenate-serrate) with acute tips. Prominent pinnate venation is recessed above and expressed below. Leaflet blades, in age, are moderately thick and glabrous, medium green above and paler below; petioles tend to be reddish on the upper side. In the fall, leaf color changes to bright and decorative shades of orange and red.

**Photo 6:** Upper leaf surfaces are shown on left, lower surfaces on right. Note prominent pinnate venation, with the distal lateral veins terminating in the tips of the teeth, and sessile to sub-sessile terminal leaflets, a critical character that separates Fragrant Sumac from Poison-Ivy. Largest leaf is 4¾ inches by 4 inches. Photo September 17.

Like most (if not all) species of Rhus (as well as Toxicodendron), Fragrant Sumac is dioecious––staminate and pistillate flowers are usually borne on separate shrubs, although plants may occasionally bear some perfect flowers (polygamo-dioecious). Closely packed flowers bloom on short compact spikes (to 2½ inches long) on twigs that appeared the previous summer. Flowers are initially hidden behind tightly clasping, dark brown, rhombic bracts that have a thick apical fringe of short tannish hairs. Spherical buds extend out from behind the bracts. Flowers uniformly unfurl all-around the spike. At the time of bloom, in March, shrubs are leafless.

**Photo 7:** This shrub has many ascending stems with floral twigs at the tips. Height of stems is 3 feet. Photo – March 11.

The small, bright yellow flowers are bowl-shaped with 5 sepals and 5 petals, as well as 5 orange nectary discs at the base of the petals. The oval to elongate-triangular yellow sepals are brown at the tip. In full bloom, the petals extend well above the sepals. Sepals and petals join below to form a short and slim greenish base. Pistillate flowers have a single compound pistil, comprising a greenish, ovoid, pubescent ovary and 3 sub-sessile yellow styles with knob-like stigmas. Staminate flowers have 5 stamens between petals and nectary discs. The pale yellow filaments arch inward so that the dark yellow anthers are directed toward the flower center.

**Photo 8:** Stems and branches have lenticels whereas fertile twigs do not. As shown, the junction of the stem with the fertile twig (on right) was the base of a petiole. A Long-Horn Bee (*Melissodes trinodis*) collects nectar. Photo March 11.

**Photo 9:** These pistillate flowers each have a single compound pistil with three knob-like stigmas. An axillary leaf scar can be seen at twig-base. Flowers are ⅛ inch wide. Note orange nectary discs at base of flowers. Photo – March 13.

**Photo 10:** Although the species is dioecious, these flowers have stamens as well as pistils (thus a perfect flower). Note brown-tipped sepals. (*Note: Fruits were not produced.*) Photo – March 15.

Fertilized flowers develop spherical (3/16 inch wide) fruits that look spiky with their dense pubescence of straight red and white hairs. Fruits (drupes), with hard, smooth stones (⅛ inch long), ripen to bright red in May, when they are relished by birds and small mammals. If uneaten, they shrivel to a dark brown (in June). Fertile twigs often persist into the next fruiting season and may, at that time, still retain remnants of fruits.

**Photo 11:** Pubescent ovaries become pubescent fruits. These twigs and three new branches are growing from axillary buds on same stem. Photo- April 9.

**Photo 12:** Mature red drupes. Bracts along the spikes still remain firmly in place even after unfertilized flowers have dropped off. Photo – May 13.

**Photo 13:** With fruit maturity, twigs die, but may remain on the shrub well into the next year. Fruits each contain a single, ⅛-inch-long, smooth, oval stone. Photo – June 6.

Fragrant Sumac is well suited for a wild garden or natural area where its persistent, slowly spreading habit does not need to be restrained. It does well in many soil types including those that are drier and rocky. Even in partial shade, it can be a nice ground cover of medium height, producing early yellow flowers, reliable summer leaves, and bright fall color. Nectar attracts many insects and the fleshy fruits provide nourishment to birds and small mammals. (The fruits also make a tangy pink lemonade for people.) If needed, stems can be fairly easily removed by pulling and clipping. It is also good for erosion control, but it is browsed by deer.

**Photo 14:** Fragrant Sumac provides excellent fall color. Photo – October 28.

Four other sumacs are found in Arkansas: 1) Tall or Midwestern Fragrant Sumac (Rhus aromatica var. serotina), 2) Winged Sumac (Rhus copallinum), 3) Smooth Sumac (Rhus glabra), and Skunk-Bush Sumac (Rhus trilobata var. trilobata). Winged Sumac and Smooth Sumac are larger, rhizomatous shrubs with pinnately-compound leaves. Skunk-Bush Sumac is similar to Fragrant Sumac in its trifoliate leaves––and has been treated as a variety of Rhus aromatica (as var. flabelliformis) in the past. However, the leaves are much smaller, and this sumac is restricted in Arkansas to chalk glades and barrens in a small portion of Little River County in the southwestern corner of the state. Tall or Midwestern Sumac, another variety of Rhus aromatica, differs from the typical variety primarily in having taller stems, leaflets with more rounded apexes, and flowers that bloom after the leaves begin to grow in the spring. In Arkansas, it grows in calcareous sites in the Ozark Highlands in the north and in the southwestern corner in the state. (Fragrant Sumac is often found in more acidic sites.) Two other species of the family that are likely to also cause confusion are Poison Oak (Toxicodendron pubescens) and Poison Ivy (Toxicodendron radicans). For comparison of these two species with Fragrant Sumac, see “Leaves of Three, Let It Be. . . . Usually”.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Shrubs | Tagged Anacardiaceae, Fragrant sumac, Know Your Natives, Rhus, Rhus aromatica | Leave a comment

Know Your Natives – Slender Mountain Mint

Posted on September 27, 2021 by ANPS Webmaster

Slender Mountain Mint (Pycnanthemum tenuifolium) of the Mint (Lamiaceae/Labiatae) family is a rhizomatous plant with narrow, linear leaves that give the plant an attractive, airy appearance. The genus name is based on Greek words for “dense” and “flower.” The specific epithet is from the Latin for “slender leaved.” The species is widespread across the eastern U.S. from east Texas and southeastern Nebraska to Maine and northern Georgia, excluding most of southern Georgia and Florida. In Arkansas, occurrence is statewide except for limited areas near the Mississippi River. Habitats may be dry to wet and sunny to partially shaded, such as prairies, roadsides, and open woodlands. It is also known as Narrow-Leaf Mountain Mint.

**Photo 1:** The many, relatively small slender leaves give the plant an airy appearance. Photo – June 14.

This herbaceous perennial grows in clonal colonies from skinny, near-surface, branching rhizomes (underground stems). New rhizomes (1/16 inch in diameter) are white, smooth, and segmented (each segment ¼ to ½ inch long), with an opposite pair of tiny triangular brown bracts subtending the segments. Rhizomes develop long fibrous roots along their distal end and, in spring, the tips of these rhizomes become emergent as single stems. During summer months, multiple new rhizomes grow from near the end of the “old” rhizome. A dense root mat may develop, especially in loose mesic soils. Dead stems persist into the new year.

,tPhoto 2: Yellow arrow indicates the “old” brown rhizome, while white arrows indicate current-year stems. New rhizomes are white, the longest one 5½ inches. Inset shows a clonal root mat. Photo – September 11.

**Photo 3:** New stems emerge while previous year’s stems still persist. Stems and leaves are glabrous. Photo – March 19.

Erect, rigid, glabrous, typically reddish stems elongate to 2 to 3+ feet tall, with short branches in opposite decussate pairs along their upper half. Each branch is subtended by a leaf. A lateral branch does not rebranch unless the stem tip has been nipped. Branching continues to the stem apex which, for a flowering stem, terminates with a single flower head. The ascending branches (the lowermost to about 5 inches long) diverge from the stem at about 60⁰. Stems are slender––near the ground, ⅛ inch or less wide, becoming wiry and thread-like distally.

**Photo 4:** With stems beginning to branch along their upper portion, colonies are leafy with an airy appearance. Plant at lower left is False Aloe. Photo – April 2.

All leaves are simple and linear. Larger leaves may be 2 inches long and less than ¼ inch wide, widest at or just below mid-leaf. From mid-leaf, the long-tapering margins extend to a more or less sharp tip; a shorter taper extends to a blunt sessile base. Leaves have a slightly recessed upper midrib and an expressed lower midrib with an obscure pair of parallel secondary veins on each side. Leaves are glabrous. Margins are entire (smooth) and slightly revolute (downturned). They turn yellow in fall. Rubbed or even crushed leaves can be nearly scentless or with a mild minty scent caused by pulegone. Plants are usually much less aromatic than other members of the genus. Lower leaves are early deciduous.

**Photo 5:** The linear sessile leaves have parallel secondary venation, as best shown by the upper surface of the second leaf from left; that leaf is 1⅞ inch long and 3/16 wide).

Flowering occurs in June into July. Clusters of flower heads (¼ inch wide) at the tips of the main stem and uppermost branches form a broad inflorescence to 3 or more inches wide. Each head consists of 20 to 50 densely packed flowers. An opposite pair of small linear leaves (about 5/16 long and 1/16 wide) occurs immediately below the sessile head. Whitish linear bracts of unequal size, in 1 to 2 series, form an involucre subtending the heads. These elongate-triangular bracts, lighter green than the leaves, are loosely imbricate with long spiny-looking tips (but not prickly).

**Photo 6:** Single flower heads terminate the main stem and uppermost branches. The densely packed heads consist of 20 to 50 flowers. An involucre of bracts subtends the heads. Photo – June 8.

**Photo 7:** Individual flower heads terminate the main stem and opposite branch pairs. Heads are subtended by an opposite pair of leaves and an involucre of spiny-looking bracts. Photo – June 18.

Flowers bloom centrifugally, from the center outward. The tubular calyx (to ¼ inch long and 1/32 inch wide) is divided above into 5 ascending, triangular lobes. Relatively large tubular corollas are white to pale lavender with an unlobed upper lip and a 3-lobed, lavender-spotted lower lip. The upper lip and lobes of the lower lip are apically rounded, with lips widely spreading to expose the throat. Attached to the corolla tube are 4 slender white filaments with 2-lobed lavender anthers exserted above the corolla. After pollen release, anthers and filaments become shriveled and brown. From the base of the 4-lobed ovary, the slender white style, with a divided apex bearing the stigmatic surfaces, extends well beyond the stamens. Exterior of the corolla as well as its throat within bear a long twisty pubescence.

**Photo 8:** Flowers are positioned with the lower lips extended away from center of the head. As shown, most anthers have become brown and styles are divided (see at upper right). Photo – June 28.

**Photo 9:** Corollas have twisty pubescence on their exteriors and within the throats. Photo – June 12.

**Photo 10:** Three-lobed lower lips often have lavender spots. As shown, corollas have dropped from most calyxes. Photo – Jun 26.

**Photo 11:** Center head on left terminates a stem with the adjacent pair of heads terminating branches. The next lower branch pair has been cut to show underside of heads. Photo – September 12.

With fertilization, each flower produces 4 tiny (1/16 inch long), black, smooth nutlets that mature in September, while stems and leaves are still green. Dispersal of the 1-seeded nutlets may be by flowing water and strong wind. Heads persists on dead leafless stems into the next growing season.

**Photo 12:** Heads become brown while stems and leaves are still green. Fertilized flowers produce tiny smooth black nutlets. Squares are ¼ inch. Photo – September 4.

**Photo 13:** Fall foliage is yellow. Leafless stems and heads persist into the next growing season. Photo – November 7.

Slender Mountain Mints are a fine addition to a wild or native garden. They are interesting and decorative as well as ecologically beneficial for a wide variety of insects seeking nectar. The species is drought tolerant and deer resistant. Self-seeding seems to be minimal, however plants can be easily propagated by division. (In loosened garden soils, Slender Mountain Mint has the potential to form vigorous colonies that may be difficult to remove due to dense root-mats.) In its natural environment, colonies persist for many years.

Five other species of Mountain Mint occur in Arkansas: 1) White-Leaf Mountain Mint (Pycnanthemum albescens), 2) Short-Tooth or Clustered Mountain Mint (P. muticum), 3) Hairy Mountain Mint (P. pilosum), 4) Whorled Mountain Mint (P. verticillatum), and 5) Virginia Mountain Mint (P. viginianum). Of these, Whorled Mountain Mint and Virginia Mountain Mint (both state species of conservation concern) are most similar to Slender Mountain Mint due to their narrow leaves. Slender Mountain Mint can be distinguished by its linear leaves less than ¼ inch wide and by its glabrous leaves and stems. Natural hybridization has been documented among native Mountain Mints, though, so difficult-to-identify plants may occasionally be encountered.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, White, Wildflowers | Tagged Know Your Natives, Lamiaceae, Mountain Mint, Pycnanthemum, Pycnanthemum tenuifolium, Slender Mountain Mint | 1 Comment

Know Your Natives – Downy Ragged Goldenrod

Posted on September 20, 2021 by ANPS Webmaster

Downy Ragged Goldenrod* (Solidago petiolaris**) of the Aster, Sunflower, or Composite (Asteraceae) family has stiff lanceolate leaves on unbranched stems that are topped by an unusually large array of golden-yellow flower heads. The genus name is based on the Latin solidus, meaning “whole,” in reference to purported health benefits of some species. The specific epithet is from the Latin for “with petiole.” In the U.S., the species occurs primarily from southern Nebraska and Texas, east to the Carolinas and northern Florida. In Arkansas, it occurs statewide except for portions of the Mississippi Alluvial Plain and Crowley’s Ridge. Preferred habitats include more or less sunny, mesic to dry, sandy to rocky areas, such as open woodlands, glades, and blufftops. It is also known as Woodland Goldenrod.

This herbaceous perennial develops a central rootstock of weakly connected segments with numerous fibrous roots. Each knobby segment bears one to several stems. Buds for the next year’s stems develop at the base of the current year’s stems. Dead stems persist into the new growth-year. Erect, fleshy springtime stems tend to be pubescent and reddish, while mature stems become reddish brown to brown below as they stiffen. Stem growth above in the inflorescence tends to be bright green before also becoming reddish to brown.

**Photo 1:** This rootstock, composed of five weakly connected segments and numerous fibrous roots, bears a dozen living stems while retaining dead stems. Round scars (at front) are remnants of three-year-old stems. Buds for next year’s stems can be seen at far right. Photo – August 20.

Stems, with slight longitudinal ridges, grow to unequal heights, often reaching 4+ feet tall and, at base, 3/16 inch in diameter. They are unbranched unless the growing tip has been damaged. Lower portion of stems typically loses leaves by mid-growth-year, becoming smooth except for projecting petiole bases. Depending on the site, they may be erect, ascending or sprawled.

**Photo 2:** Springtime leaves and stems bear short pubescence, becoming glabrate as plants mature, except for leaf margins. Photo – April 8.

Plants have alternate, simple stem leaves, narrowly elliptic, spreading to ascending, and stiff, at midstem to 4 inches long and ½ inch wide, gradually decreasing to as little as ⅛ inch long in the terminal inflorescence. They are sessile to short-petiolate, with margins entire (smooth) to shallowly serrate distally, the teeth mucronate. Upper leaf surface is green with a satin sheen, the lower surface with a dull sheen. Venation is pinnate with a single strong midvein and secondary veins that curve forward to parallel the margins. Mature leaves feel slightly rough from microscopic hispid pubescence, with hairs more prominent on the main veins beneath. Margins are ciliate with the hairs angled toward the apex. As soil dries during summer, leaf-drop proceeds up-stem.

**Photo 3:** Stems have closely spaced narrowly elliptic, simple leaves that extend from stem base into the inflorescence. Dead stems persist into the new growth year. Photo – March 4.

**Photo 4:** Upper surface of a 2½ inch leaf shown above, the lower surface below. Ciliate pubescence of upper leaf can be better seen in its shadow. Secondary veins curve and parallel the margins. Tertiary veins are reticulate. Photo – August 28.

**Photo 5:** Set of three leaves at top, left and right are from different plants. Left leaves are serrate while top and right leaves are entire. Margins are narrowly downturned, as can be seen on lower left leaf. The lower stem segment is 3⅛ inches long and 3/16 inch wide. Pubescence is not visible on leaves or stem. Photo – August 31.

Composite flower heads, with ray and disk florets, bloom in September and October. The axillary inflorescence, along the upper portion of the stem, consists of individual flower heads and tightly branching clusters of 3 to 7 flower heads, forming columnar or spikelike panicles. An inflorescence may be 4 to 10 inches long with up to 150+ heads, the flowering proceeding from apex to base. Individual heads or clusters are subtended by a small leaflike bract. While pedicels of single flower heads are consistently short, peduncles of clusters may be a bit longer (to ½+ inch). When plants are erect, flower heads are arranged equally around the stem; when sprawled, heads twist toward sunlight so that the inflorescence is secund (heads all on upper side). Pedicels and peduncles bear closely spaced linear-oblong bracts that transition to the linear-lanceolate phyllaries of the involucre (to ¼ inch long). Heads are about ¼ inch long and ⅛+ inch wide. Pedicels, peduncles, bracts, and phyllaries are light green with short hooked pubescence, that of the phyllaries being glandular.

**Photo 6:** Developing inflorescence of two stems at left consists of individual flower heads. Tip of stem at right was apparently damaged, so that lateral branches developed. Stem leaves may continue into the inflorescence (right stem) or transition to bracts (left stems). Photo – August 26.

**Photo 7:** Flowerheads on spreading to sprawled stems twist sunward so that the inflorescence is secund, but leaves remain arrayed about the stem. Plant at lower right is Goat’s Rue. Shrubs are Sparkleberry. Photo – October 25.

**Photo 8:** Flowers of this inflorescence (a panicle) are in tightly branched clusters, the distal heads blooming first. Blooming sequence of inflorescences begins at the apex. Photo – September 7.

The golden yellow flower heads comprise 5-10 pistillate (with pistils only) ray florets that surround 8-18 perfect (with pistils and stamens) disk florets subtended by an elongate cuplike involucre. The involucral bracts (termed phyllaries in the composites) are disposed in 3-4 series, with spreading to sharply recurved, triangular tips that give the heads a bristly appearance. Inner and outer surface of phyllaries bear minute glandular pubescence which may cause them to feel viscid. Heads bloom centripetally, from the ray florets inward to the center. Ray florets have a single linear to oblong ligule (the exposed portion of the corolla), ¼+ inch long, that has several longitudinal pleats, a rounded apex and tapered base.

Disk florets have tubular corollas, 5 stamens (filaments + anthers) and 1 pistil (ovary + style + stigma). The corollas, about 3/16 inch long, are topped with five narrow, erect, triangular lobes. Anthers of the free staminal filaments are fused together into a ring surrounding the style. As the style elongates through the anther ring, it carries the pollen above the corolla, where it is available to be dispersed by pollinators. With pollen released, anthers wither and the exserted style narrowly bifurcates to expose linear stigmatic surfaces for pollen capture. Corollas of disk florets are surrounded by a pappus of straight hairs, attached to the summit of the inferior ovary.

**Photo 9:** Clusters of flower heads seen from below and above. Pedicels and peduncles bear bracts that transition to the overlapping phyllaries. Bifurcated styles of two ray flowers can be seen in lowermost flower head. A number of slightly bifurcated styles of disk florets can also be seen. Photo – October 3.

**Photo 10:** Flower head shows: 1) flowering sequence moving from ray florets toward center of head, 2) 5 lobes of the tubular disk florets, 3) raised margin of disk corolla lobes, 4) slender filaments and anther rings, and 5) extruded pollen (far right). Elsewhere: 1) hooked ciliate pubescence on leaf (lower left) and 2) glandular pubescence on recurved phyllaries (upper left). Photo – October 18.

Fertilized ray and disk florets produce flattened elongate achenes (referred to as cypselae in Aster family) topped by pappus. The ⅛ inch long achenes are longitudinally ribbed. Dry pappus radiates from the apex of the achene where it provides lift for wind dispersal.

**Photo 11:** As flower heads dry, the enlarging ovaries/cypselae bulge upward as the exposed pappus dries and radiates from summit of the elongate cypselae. Photo – November 11.

Downy Ragged Goldenrod, with its large and decorative, late-summer and fall inflorescence, is an excellent choice for a wildflower garden. As with other goldenrods, its flowers provide nectar and pollen for a wide variety of insects, and seeds are consumed by small song birds. The long graceful stems can be somewhat “disorganized” so that staking may be needed. Plants do not spread by rhizomes. When soil dries, this species seems to be more prone to leaf drop.

Downy Ragged Goldenrod is one of some 30 or more species, subspecies, and varieties in the Solidago genus recognized in Arkansas. Of all these species, it most closely resembles Buckley’s Goldenrod (Solidago buckleyi) which has a similar inflorescence and spreading to recurved phyllaries. Buckley’s Goldenrod has fewer and significantly larger and thinner leaves that consistently have prominent marginal teeth.

*“Downy” may be a reference to early pubescence of stems and leaves which is mostly lost with plant maturity. “Ragged” may be based on the plant’s overall appearance at bloom-time: its long unbranched stems of varying lengths; its firmly positioned, often sprawling and twisty stems; and leaves that drop as available moisture declines.

** Leaf and phyllary shape and pubescence are variable across its range. Some authorities recognize varieties that are not addressed here. Arkansas plants are in need of further study.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Wildflowers, Yellow | Tagged Asteraceae, Downy Ragged Goldenrod, goldenrod, Solidago, Solidago petiolaris | 1 Comment

Know Your Natives – Late Boneset

Posted on August 31, 2021 by ANPS Webmaster

Late Boneset (Eupatorium serotinum) of the Aster, Sunflower, or Composite (Asteraceae) family is a tall herbaceous perennial with small, clustered, whitish flowerheads that lack ray florets. The genus name recognizes Mithridates Eupator who invented a “universal antidote” against poisoning and is said to have used a species of the genus in medicine. The specific epithet translates as “developing late” in reference to the time of flowering. The species is wide-ranging, from the Big Bend area of Texas to Illinois, east to the Atlantic and Gulf Coasts, and including most of Florida. In Arkansas, it occurs statewide. The common name “boneset” originates from past use of some species of the genus to relieve pain. Plants are common in a variety of open to partly shaded habitats––prairies, woodlands, rights-of-way, roadsides and fallow fields––on mesic to dry soils.

Young single-stem plants have a stubby central rootstock with long near-surface spreading fibrous roots. At the end of the growing year, stems die with new stems developing the following spring from bases of the old stems. Over time, this short-lived perennial develops a gnarly central rootstock supported by a mass of wide-spreading fibrous to ropy light-tan roots. As new stems develop, the older central portion of the rootstock decays.

**Photo 1:** New stems grow from base of dead stems as the central portion of the rootstock decays. Width of that portion of the root mat shown is 7 inches. Photo – August 14.

Plants, lacking basal leaves, have one to several stems that may be 2-6+ feet tall, those in mesic soils being taller. Early in the growing season, stems tend to be purple, but later become medium green with faint, reddish ridges. Main stems are straight and erect, with their upper half to two-thirds bearing opposite pairs of spreading to ascending, axillary (primary) branches that decrease distally in length. More robust plants branch more profusely. All branches typically terminate in an inflorescence. Near the branch tips, leaves and branches may become sub-opposite or even alternate. Stems and branches are uniformly puberulent.

**Photo 2:** As an herbaceous perennial, new spring growth originates directly from the rootstock. Plants do not have basal leaves. Photo – March 28.

**Photo 3:** Leaves are in matched decussate pairs, except that those near the tips of branches may be sub-opposite or even alternate. Photo – May 10.

**Photo 4:** Stems are erect throughout the growth-year. As shown, branches have begun to grow along the stem’s upper portions. Stems, early in the growth year, are a solid purple. Photo – June 3.

Leaves are decussate, petiolate, and broadly lanceolate to lanceolate, becoming narrower above. A typical larger lower stem leaf may be 9½ inches long (including a 2½-inch petiole) and 2½ inches wide. An upper leaf, at the base of the inflorescence, may be 1⅝ inches long (including a ¼-inch petiole) and ¼ inch wide, while the uppermost leaves (subtending the final floral branches) become tiny and almost linear. Margins of larger leaves are boldly serrate while those of smaller leaves become entire. Margins taper gently to acute apexes. Upper leaf surface is glabrous, lower surface and underside of petioles puberulent. Upper surface is a shiny green, lower surface a dull pale green with the main veins yellowish green. Venation, recessed above and expressed below, is longitudinal with 2-4 secondary veins parallel to the midrib. Petioles are swollen and clasping at the base. Lower stem leaves that do not subtend a branch, tend to subtend a rudimentary branch or tuft of leaves. With drying conditions, lower leaves drop off.

**Photo 5:** Paired decussate branches are subtended by paired decussate leaves. Note stem puberulence and somewhat clasping bases of petioles. Photo – July 12.

**Photo 6:** Lower stem leaves, mid-stem leaves, and upper-branch leaves, the upper surfaces shown on left, lower surfaces on right. Larger blades are widest just above base. Venation is longitudinal. Leaf at left is 7¼ inches long, including a 1⅞ inch petiole.

Plants flower from mid-August into October. Spreading clusters of small flowerheads arranged in corymbs at the branch tips produce a broad, flat-topped inflorescence. Corymbs, with 6-10 closely spaced flowerheads, bloom outward from the base. Each head comprises 8-15 disk florets; ray florets are absent. Inflorescence branches, peduncles and pedicels are clothed in a fine white puberulence.

**Photo 7:** Display of parts of a 5½ foot stem. The ¾-inch-diameter stem at left, lower leaves having dropped off, was at ground level. Paired branching (lower right) is consistently repeated into the inflorescence (upper center). Photo – August 8.

**Photo 8:** The overall inflorescence tends to be flat-topped. The inflorescence is an insect magnet and provides a hunting ground for this White Banded Crab Spider (*Misumenoides formosipes*). Photo – September 24.

**Photo 9:** Terminal clusters are composed of several corymbs, each having 6-10 flowerheads, each composed of 8-15 disk florets. All parts of the inflorescence below the corolla are densely puberulent. Photo – September 6.

Disk florets, with whitish, 5-lobed, tubular corollas, are set in a cylindrical involucre of up to a dozen imbricate, elliptical phyllaries, about ⅛ inch long, in 1-2 series. Purplish stamens remain hidden within the corolla throat. The white style pushes upward through the ring of fused anthers, at first displaying the pollen, and ultimately dividing and spreading to receive pollen from other florets.

**Photo 10:** Disk florets, with white, 5-lobed, tubular corollas, are packed in a cylindrical involucre. Stamens and bristly pappus are hidden at this stage of floral development. The divided style arms extend well beyond the corollas. Photo – September 6.

After fertilization, corolla, stamens and style are shed from the inferior ovary as the pappus of 20+ white hairs or bristles dries and radiates from its apex. Ovaries mature into dark brown, cylindrical, slightly ribbed achenes, less than 1/16 inch long, dispersed by wind.

**Photo 11:** As the stem dies, the pappus radiates from the top of the achenes, providing lift and wind dispersal. Photo – November 13.

In considering Late Boneset for a garden, there is a good chance that volunteer plants are already there. Multiple plants may create a weedy appearance, but individual plants can be attractive as specimens, especially where associated with other native plants of differing texture, structure and color. Bonesets, mostly avoided by deer, are attractive to many insects. Removal of the dying stems from this short-lived perennial before seed dispersal would help control self-seeding.

**Photo 12:** In this garden setting Late Boneset grows with False Aloe, Dittany, Rose Vervain, Hairy Blazing Star, and Hairy Skullcap. Photo – July 18.

Late Boneset is one of some 20 species and recognized hybrids in the genus Eupatorium that occur in Arkansas. Many of these other species have white flower heads that are similar to those of Late Boneset. The leaf characteristics of Late Boneset––the undivided blades, long petioles and marginal serrations––separate it from most of those other species.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, White, Wildflowers | Tagged Asteraceae, Eupatorium serotinum, Know Your Natives, Late Boneset | Leave a comment

Know Your Natives – Mexican Hat

Posted on August 24, 2021 by ANPS Webmaster

Mexican Hat (Ratibida columnifera) of the Aster, Sunflower, or Composite (Asteraceae) family is a perennial species that has flowerheads with a columnar central receptacle (disk). The origin of the genus name, coined by the eccentric naturalist Constantine Rafinesque-Schmaltz, is not entirely clear, although it may be a modification of a first century name for an aster-like plant from an area that is now in Romania. The specific epithet translates to “in the shape of a column,” a reference to the central disk. The primary natural range of the species is believed to be a broad swath from northern and eastern Mexico to south-central Canada, that includes the Great Plains of the U.S., with additional widely scattered occurrences both eastward and westward to the Atlantic and Pacific Coasts. Some of these populations, especially nearer the core range, may be natural, but the species is widely cultivated as an ornamental, particularly in wildflower seed mixes, so the precise natural limits are obscured. In Arkansas, it is widely scattered across the state with the greatest concentrations in the Ozark Highlands and the southwest Blackland Prairie region. It may be indigenous to native grasslands in those areas, but is also often found along roadsides and other rights-of-way. Alternative common names include Long-Head Coneflower and Prairie Coneflower.

New spring growth arises from a smooth, yellow-tan, minimally branched taproot with numerous small secondary roots. Growth begins with one to several, early-deciduous, basal rosettes of leaves, that produce one to several, erect, sparsely branched stems, growing to 3 feet tall. Larger stems are ridged, becoming 4-5-sided. Minute strigose pubescence (short appressed hairs) gives them a rough feel. Plants have an open appearance due to leaf size decreasing distally. Dead stems persist well into the next year.

**Photo 1:** Rosettes of spring-time basal leaves surround developing stems. Photo – Mar 11.

**Photo 2:** Basal leaves transition to cauline leaves. Basal leaves are early-deciduous. Dead stems persist from the previous growth-year. Photo – April 13.

**Photo 3:** This plant has two stems (and a dead stem behind) growing directly from the rootstock. The smooth yellow-tan taproot has a few branches and numerous small ropy roots. Note that basal leaves have been lost. Photo June 30.

Basal and stem leaves are deeply pinnately incised with up to 15 mostly opposite, linear to linear-oblong lobes. A larger stem leaf may be 5 inches long and 3 inches wide with individual lobes to 2 inches long and 3/16 inch wide. Leaf number, size and lobing decrease distally––upper stems are leafless and uppermost leaves may consist of a single “lobe.” Lobes are apically rounded. Leaves are medium green on both surfaces with the proximal portion of the rachis trending to white. Other than midribs, venation is obscure. Like the stems, leaves are covered above and below with fine strigose pubescence and feel rough. Narrow wings extend along the rachis from the base of the lobes. While basal leaves have relatively long petioles, stem leaves become short-stalked to sessile.

**Photo 4:** Stem leaves are deeply incised so that linear lobes are formed. Sessile leaf at right (showing abaxial side) is 3⅞ inches long and 3 inches wide. Petiolate leaf at left attaches to a square stem. (For shape of basal leaves, see Photo 1.) Photo – July 19.

The inflorescence, from late May into late July, consists of composite flowerheads at the tips of tough erect peduncles that may be several inches to a foot long. Heads consist of a central columnar disk to 2 inches long and ⅜ inch wide, with numerous disk florets, surrounded by 4 to 12 sterile ray florets (lacking stamens and pistils). The disk, before opening of its florets, has a patterned surface that is pale green to gray-green. Ray florets consist of round to ovate ligules with a notched apex and clawed base. They may be well-spaced to overlapping, becoming ruffled to misshapen when crowded. Plant-specific petal coloration varies from rich brownish reds with yellow borders to solid brownish red or solid yellow*. Heads have a variable number of tough lanceolate phyllaries (usually five) of various sizes that are ascending while the head is in bud, but become spreading at anthesis. Minute strigose pubescence that covers peduncles and phyllaries extends onto the central disk.

**Photo 5:** Developing buds of disk florets roughen surface of the columnar disks. Phyllaries shift from ascending to perpendicular to the head’s axis. Note ray petals on heads at right. (Leaf on stem/peduncle on left partially removed.) Photo – July 19.

**Photo 6:** Composite flowerheads, terminating stems, have central columnar disks to 2 inches long and ⅜ inch wide. With crowding, ligules become misshapen. Photo site – Cove Lake spillway (Logan County). Photo – June 8.

The several hundred closely spaced, spirally arranged disk florets reach anthesis in longitudinal “bands” from the disk base upwards. Calyxes (< 1/16 inch long), with a minute pedicel, comprise 5 pale green elongate sepals with knobbed apexes. A tight staminal column of five purple filaments (twice as long as the sepals) extend from each disk flower. Pollen-bearing anthers face inward. As the reddish purple style develops, it pushes through the staminal column and releases the pollen. After the pollen is displayed, the style branches and recurves to expose reddish purple, linear stigmatic surfaces.

**Photo 7:** Disk florets bloom in longitudinal bands, beginning at disk base. Ligule color, consisting of rich brownish reds and yellows, is plant-specific.

**Photo 8:** The lowest band of disk florets has partially exserted styles. Florets in the above band are topped by pollen pushed-out by near-exserted styles. Minute strigose pubescence occurs on peduncle, phyllaries and receptacle.

**Photo 9:** Florets below the uppermost, open, pollen-topped florets have their elongate stigmatic surfaces exposed. Star pattern of extruded pollen reflects the 5 anthers.

**Photo 10:** Disk floret calyxes have five elongate sepals with knobby apexes set on a slim base. Receptacle, between florets, is covered with minute pubescence. Photo – July 20.

Most disk florets do not seem to produce viable fruit. When fertilized, florets produce a flattened chevron-shaped achene to ⅛ inch long and half as wide. These elongate brown fruits have a rounded base and a flat apex which may have a pappus of 2 weak awns. Dispersal of seeds is probably by birds, gusty wind and surface-water flow.

**Photo 11:** Central disk divided to show internal structure and ovules. Upper (left) and lower (right) surfaces of ray corollas shown. Clawed bases of ray corollas mostly still attached to head.

**Photo 12:** Flowerheads and peduncles dry quickly after flowering. The flattened 1-seeded achenes (the “sunflower seeds”) have a chevron shape. Head on left did not produce viable fruits. Photo – July 19

With its colorful flowerheads and compact structure, Mexican Hat is commonly included in gardens, including native plant gardens. The plant prefers sunny sites with well drained soils, but will survive in partially shady sites and short-term dry conditions. Apparently it is not an aggressive self-seeder.

In addition to Mexican Hat, one additional member of the genus occurs in Arkansas, Gray-Head Coneflower (Ratibida pinnata). Gray-Head Coneflower is a taller plant with fibrous roots, leaves with broader lanceolate lobes, solid yellow ray flowers, and shorter, more rounded central disks.

*Some authorities identify plants with yellow ligules as R. columnifera forma columnifera and those with reddish brown ligules with yellow edges as R. columnifera forma pulcherrima.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Wildflowers, Yellow | Tagged Asteraceae, Know Your Natives, Ratibida, Ratibida pinnata | Leave a comment

Know Your Natives – Betony-Leaf Noseburn

Posted on August 14, 2021 by ANPS Webmaster

Betony-Leaf Noseburn (Tragia betonicifolia) of the Spurge (Euphorbiaceae) family is a perennial monoecious forb that is well-clad in stinging hairs. The genus name honors Hieronymus Tragus (aka Hieronymus Bock, a 16th-century German botanist). The species epithet is Latin for “betony leaved” and associates the appearance of leaves of this species to the Eurasian Betony (Betonica officinalis). The species occurs in the south-central U.S. from Texas and Louisiana north to Kansas and Missouri, with disjunct occurrences in Tennessee. In Arkansas, it occurs in well-drained areas of the western West Gulf Coastal Plain but primarily throughout large sections of the Interior Highlands. Preferred habitats include dry sandy to rocky soils in prairies, woodland openings, and glades, in both acidic and basic soils.

Betony-Leaf Noseburn, with long-ropy descending and spreading branched roots and stout caudex, is inconspicuous when growing with other species of similar height. It is a lanky, multi-stemmed plant. Early stems are erect but become leaning with growth, unless supported. Depending on environment and degree of support and shading, stems, grow to 2½ feet tall and have a near-ground diameter of about 1/16 inch. They are terete in cross-section, medium green, unbranched or sparsely branched, with closely spaced, slight longitudinal ridges. Branches, mostly about mid-stem, are axillary to alternate leaves. The stems and branches may twine. The entire plant, to varying degrees, has a fine translucent pubescence with stinging hairs. Hairs on stems align with the longitudinal ridges. Winter-killed stems persist well into the next growth year(s) so that the caudex is spiky.

yPhoto 1: The branched ropy roots of this plant grew in a rock-free, fine-sandy soil. Dead stems of the previous year persist, along with stumps of earlier years. Photo July 12.

**Photo 2:** Spring growth is heavily pubescent. This same plant is shown in Photo 1. Photo – May 14.

**Photo 3:** These two stems, growing with support, developed long axillary branches. Left stem is 30 inches long with 21 inches shown. Photo – July 13.

The lanceolate to broadly lanceolate alternate leaves, to 2½ inches long and 1 inch wide (including petioles to ¾ inch), have acuminate apexes and, typically, cordate bases. Pinnate venation is recessed above and strongly expressed below. Lateral margins have prominent round-triangular serrations with tiny pin-tips––the termination of secondary veins. Straight slender petioles (1/32 inch wide) are ascending at 45⁰, but the blade midribs arch downward so that the entire leaf blade is angled downward. Upper and lower leaf surfaces are a medium green with the lower surface duller. Pubescence of upper blade surface is very short, sparse and appressed while that of the lower surface is significantly longer and dense along major veins. Leaves are well spaced at ½ to 2 inches apart. A pair of lanceolate stipules, less than ⅛ inch long, occurs at the base of leaves, but dry and wither during the growing season.

**Photo 4:** Leaves typically have cordate bases. Prominent pinnate venation is recessed above and strongly expressed below. Stems, along with other parts of the plant, are densely pubescent with stinging hairs. Photo – May 30.

**Photo 5:** Right leaf pair are from low on stem while left pair is from mid-stem. A terminal stem segment is shown above. Stipules at base of petioles have dried. Photo – July 14.

With indeterminate plant growth, flowering may continue at the ends of stems from spring into summer. Whereas branches are axillary, the inflorescence is borne on short leafless stems (floral stems) growing opposite leaf-bases. Floral stems, to about ¾ inch long, develop along with leaves at the elongating tips of stems and branches. Near the base of floral stems, a “limb,” with several linear bracts, diverges from the main stem to a pedicel (marked by a joint) that supports a pistillate flower (see Photo 7). From the base of the limb, the floral stem continues as a raceme bearing 10 to 30 staminate flowers. Staminate flowers on stubby pedicels are subtended by linear bracts. Floral stems, limbs, pedicels and bracts are a medium green with dense straight to twisty stinging pubescence.

**Photo 6:** Floral stems, growing opposite leaf bases, develop when leaves appear at tips of elongating stems. Several floral stems, about ¾ inch long, can be seen on which staminate flowers have dropped as fruits mature. Photo – July 14.

The ovary of a pistillate flower comprises 3 large spherical, joined carpels which have a dense covering of large, translucent, stinging hairs. Pistillate flowers, set on a calyx composed of about five elongate-triangular sepals, lack petals and have a central set of three fused stubby styles; each topped with a spreading stigma.

**Photo 7:** Floral stems bear a pistillate flower and a raceme of staminate flowers. Red arrow indicates pedicel of the pistillate flower. Yellow arrow indicates pedicel of a discarded staminate flower. Note bracts subtending staminate flowers and bracts on “limb” below pistillate flower. Photo – June 30.

**Photo 8:** Pistillate flowers have 3 fused styles, each topped with an outward-spreading stigma. Longest hairs occur on fruit. Photo – June 30.

Staminate flowers bloom sequentially from raceme base to apex and may complete flowering before the pistillate flower reaches anthesis. The less than 1/16-inch-wide greenish yellow staminate flowers have 3 sepals, no petals, and 3 paddle-shaped pale yellow filaments topped with pale yellow anthers with the shape of a vertically oriented knob. Sepals, flared and petal-like, join to form a tube attached to a very stubby pedicel. With the passing of anthesis, staminate flowers drop off, leaving short, stubby pedicels and subtending dark green lanceolate bracts. The pedicels of Betony-Leaf Noseburn are considerably shorter than the bracts, a helpful trait for identifying the species. The empty raceme persists as the fruits dry.

**Photo 9:** The greenish yellow staminate flowers, less than 1/16 inch wide, have 3 sepals and stamens. Once the pale yellow pollen is released, flowers quickly drop off. Photo – June 30.

With fertilization, a 3-chambered, green, 1/4-inch seed capsule develops, becoming tan as it dries and matures. Capsules kinetically dehisce, resulting in a partial separation of the two sections of each chamber and a small “blow-out” of the lower portion of each chamber. Each chamber produces a single seed. With seeds dispersed, the “damaged” chambers drop to the ground, still intact. The black spherical seeds (⅛+ inch in diameter) are hard with a thin, elongate hilum.

**Photo 10:** On left, floral stem grows opposite a leaf that has a pair of stipules at its base. Staminate flowers have dropped off the raceme as fruit matures. Central scar of the styles can be seen on fruit at right. Photo – August 17.

**Photo 11:** When dry, simultaneously, chambers kinetically dehisce with seams widening slightly as seeds are ejected through the chambers’ bases. The black spherical seeds are hard with a thin, elongate hilum. Squares = ¼ inch. Photo – July 14.

For gardening purposes, this interesting plant should probably be relegated to a naturalistic garden where it would not likely come in contact with people. A slight touch of its stinging hairs to wrists, ankles, etc. can cause irritation for 10 to 15 minutes. Another species with stinging hairs addressed by this series of articles is Wood Nettle (Laportea canadensis).

Four other species of Noseburn occur in Arkansas: Heart-Leaf Noseburn (T. cordata), Branched Noseburn (T. ramosa), Small’s Noseburn (T. smallii), and Nettle-Leaf Noseburn (T. urticifolia). Heart-Leaf Noseburn has large, heart-shaped leaves with long acuminate tips and numerous teeth per side. It grows in moist forests in several areas of the state. Branched Noseburn has linear leaves. It is found primarily in calcareous glades in the Ozark Highlands. Small’s Noseburn has rounded leaves with few, broad teeth. In Arkansas, it is found only in the sandhills of Miller County and is a state species of conservation concern. Nettle-Leaf Noseburn is the most similar to and easily confused with Betony-Leaf Noseburn. The primary character that distinguishes it is that the staminate flower pedicels of Nettle-Leaf Noseburn are about equal to or slightly exceed the bracts. Nettle-Leaf Noseburn is found primarily in better drained areas of the West Gulf Coastal Plain and southern Ouachita Mountains, in primarily acidic soils.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, Wildflowers, Yellow | Tagged Euphorbiaceae, Know Your Natives, Noseburn, Tragia, Tragia betonicifolia | Leave a comment

Know Your Natives – Rattlesnake Master

Posted on July 22, 2021 by ANPS Webmaster

Rattlesnake Master (Eryngium yuccifolium) of the Parsley or Carrot (Apiaceae) family is a tall perennial with distinctive ovoid flower heads. The genus name is based on the ancient Greek name used by Theophrastus for a prickly plant of the Mediterranean region. The specific epithet is Latin for “yucca-leaved”––morphologically true, although the two groups are unrelated: despite its strap-shaped, parallel-veined, monocot-looking leaves, Rattlesnake Master is a dicot. The common name is based on use of the plant by Native Americans to treat snakebites, for protection from being bitten, or for controlling snakes during ceremonies. In the U.S., the species grows principally from eastern Texas north into Iowa and east to Indiana, North Carolina, and Florida. In Arkansas, it occurs statewide. Habitats vary from sunny to partially shaded prairies, savannas and open woodlands, to stream banks and roadsides, in a broad variety of dry to wet soils. It is also known as Button Eryngo.

**Photo 1:** These four-year-old plants are in a restored prairie that has deep, well-drained sandy soil. The plant second from left, 5¾ feet tall, was excavated to expose roots (see Photo 2). Photo – June 28.

The glabrous (hairless) plants may have ropy roots only (observed in well-drained sandy soils) or corms and ropy roots (observed in wet soils). With ropy roots only, at shallow depth, roots radiate from the base of the stem, lacking a taproot. Corms, when present, grow to 2 inches long and ¾ inch wide, typically decaying after several years. These near-surface tan to brown corms have descending ropy roots attached to the base of stems or along the lower side of the corms. Individual corms bear a stem or two. At the end of the growth year, stems die and drop off, leaving round scars on the corm’s upper surface with rough end scars marking where the older corm rotted away. With clonal corms increasing in number over the years, a dense cluster of plants may develop.

**Photo 2:** This plant, along with a second plant from the same area (see Photo 1), has ropy roots only. Stem base is 1¼ inches wide. Photo – June 28.

**Photo 3:** Rootstock of this two-year old plant consists of a corm and ropy roots. The dead base of the previous year’s stem and a bud for the next-year stem can be seen. Inset shows corms separated from a tight clump of 20+ corms. Photo – June 30.

Leaves and stems decline at the end of the growing season (August) as new basal rosettes appear and persist over winter. In late winter, stems begin to grow from the basal rosettes. In more favorable sites, stems may grow to 5+ feet tall. The round, pale green stems have alternate, cyclically arranged leaves separated by ½ inch near the base to 12 inches distally. Stems are straight, stout, smooth, and hollow between the nodes (fistulose).

**Photo 4:** After surviving over winter, basal rosettes rise alongside the previous year’s dead stems. Photo – March 12.

Leathery, strap-like basal and stem leaves are pale green to bluish green, usually with a waxy, white coating (glaucous) on both surfaces. Venation is parallel, without a notable midrib. Larger leaves have widely spaced, weak marginal spines with fine tips, ½ to ¾ inch long near the leaf base. Stem leaves, arranged cyclically, with broad, clasping bases grow to 3 feet long and 1 to 1¾ inches wide. Basal leaves tend to decline as the stem continues to grow.

**Photo 5:** The alternate stem leaves, clasping to sheathing, are arranged in a cyclic pattern. Leaves, with weak marginal and apical spines, tend to be glaucous. Photo – May 26.

The stem terminates in a flower head. Along the upper portion of the stem, 1-5 lateral branches bear additional terminal heads, with some stems containing as many as 20+ heads on stout, straight peduncles.

**Photo 6:** This 5½-foot tall plant with five stems is growing in a sandy, rocky site. The longer stem leaves droop toward the ground. Longest leaves are 29 inches. Photo – June 30.

Flowering occurs in late June into August. The primary inflorescence consists of heads with 90± tiny (3/16 inch long, 2/16 inch wide) densely packed flowers (morphologically, the heads are condensed umbels) in which the sessile flowers are attached to a spongy core (the receptacle). Each flower is subtended by a triangular pointed bract (floral bract). The upright heads, ¾ to 1 inch wide and high, are subtended by elongate-triangular overlapping basal bracts. Floral bracts and basal bracts have firm pointed tips so that the heads feel prickly.

**Photo 7:** Floral branches may be alternate, opposite or whored. Each branch is subtended by a leaf-like bract with a cupping base and multiple apical spines. Photo – June 24.

The perfect flowers (with pistils and stamens) have 5 sepals, 5 petals, 5 stamens (filaments + anthers), and 1 compound pistil (ovary + styles + stigmas) of 2 carpels. Greenish white sepals and white petals are attached at the top of the ovary––the ovary is “inferior,” the flowers “epigynous.” The white styles (obscurely tipped with stigmas) appear several days to a week before the stamens. The white hair-like filaments, twice as long as the styles, hold the relatively large, tan, 2-lobed anthers well above the corolla.

**Photo 8:** Each tiny flower is subtended by a pointed pale green bract. Pairs of styles appear before stamens. Several tan anthers can be seen around the head’s perimeter. Photo – July 5.

**Photo 9:** Upper portions of the white petals are notched. Styles stand-out in lower portion of photo. The greenish sepals surround the petals. Photo – July 11.

**Photo 10:** Heads are subtended by overlapping bracts. Note paired styles and several anthers. Photo – July 5.

**Photo 11:** Sessile flowers connect directly to a spongy receptacle. Morphologically, flower heads are condensed umbels. Persistent sepals and petals become bract-like around the developing fruit. Photo – August 23.

With fertilization, flowers produce a schizocarp-type fruit which splits into 2 dry, indehiscent, 1-seeded mericarps (a diagnostic feature of the parsley family). The obovate mericarps have a flattened interior side and two exterior sides which are densely scaly with persistent sepals and petals. This scaly texture may help mericarps disperse by wind, water and animals. With the scales removed, mericarps are ⅛ inch long and half as wide.

**Photo 12:** Dry fruits of the head on left have been removed to expose a pineapple-looking receptacle. Separated mericarps are shown, along with three dislodged seeds on left. Photo – October 14.

For a garden, Rattlesnake Master would be an excellent specimen plant where its color and distinct structure would provide strong contrast with other plants. It is a stand-out plant throughout the growing season into winter. It has a high germination rate so that extra plants may be gifted to other native plant gardeners. It is not eaten by deer.

Four other native species of the genus are found in Arkansas: Hooker’s Eryngo (Eryngium hookeri), Blue-Flower Eryngo (Eryngium integrifolium), Leavenworth’s Eryngo (Eryngium leavenworthii), and Creeping Eryngo (Eryngium prostratum). The first three are rare in the southern part of the state and of conservation concern. They are smaller plants, often with bluish or purplish inflorescences. Creeping Eryngo, a very small, sprawling plant also with bluish flower heads, is known throughout most of the state. Rattlesnake Master is easily distinguished by its large size and consistently white heads.

Article and photographs by ANPS member Sid Vogelpohl

Posted in Know Your Natives, Native Plants, White, Wildflowers | Tagged Apiaceae, Eryngium, Eryngium yuccifolium, Know Your Natives, Rattlesnake Master | Leave a comment

Arkansas Native Plant Society

Know Your Natives – Winged Sumac

Know Your Natives – Carolina Buckthorn

Know Your Natives – Hairy Bush Clover

Know Your Natives – Fragrant Sumac

Know Your Natives – Slender Mountain Mint

Know Your Natives – Downy Ragged Goldenrod

Know Your Natives – Late Boneset

Know Your Natives – Mexican Hat

Know Your Natives – Betony-Leaf Noseburn

Know Your Natives – Rattlesnake Master

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