Know Your Natives – Woodland Sunflower – Helianthus strumosus

Helianthus strumosus, known by the common name pale-leaf woodland sunflower or just woodland sunflower (a general name also used for several other native species of sunflowers), of the Aster (Asteraceae) family, is a deciduous rhizomatous perennial which occurs throughout the eastern U.S. from eastern Texas and North Dakota to the Atlantic and Gulf Coasts.  In Arkansas, it is reported from across much of the state and possibly occurs statewide.  The genus name is based on Greek words for “sun” and “flower”.  The specific epithet relates to having strumae (cushion-like swellings) at the base of hairs on the upper stems.  This plant is usually found in full to partial sun in dry to mesic soils of open woods, glades, prairies, roadsides and river banks.

The plant, a colonizer with rigid, straight, rounded (terete) stems, grows to 5 feet or more tall and tends to lean.  Stems and secondary floral branches vary from glabrous to scabrous and may be partially covered with a bluish waxy coating (glaucous).  Winter-killed stems remain upright into the following year.

Woodland sunflower - Helianthus strumosusPhoto 1:  New stems of Helianthus strumosus grow from rhizomes in mid-April.

Opposite, widely-spaced, rough leaves are medium green on the upper surfaces and lighter green on the lower surfaces.  Pairs of leaves are off-set 90 degrees from the pair immediately below or above.  Leaf margins are mostly entire, but also may have shallow, widely-spread teeth (serrations).  Lanceolate stem leaves with broadened bases range from 5½ inches long and 1½ inches wide to 8 inches long and 3¼ inches wide.  From their broadest dimension near the base, leaves have a gentle taper to a long-pointed (acuminate) tip, while below that point the width sharply tapers toward the midrib before continuing at a more gentle taper onto the petiole.  Petioles, including the winged portion, range from ¼ inch to 1 inch long.  Hairs on the upper and lower leaf surfaces are stiff and hooked, and thus the leaves feel scabrous.  Longer hairs occur on leaf margins and along abaxial (underside) veins.  Leaves, when gently pulled between fingers, will not slide.  Primary veins consist of three prominent veins; namely, the central vein (midrib) and a pair of lateral veins that originate near the base of leaf but well within the leaf blade.  The two primary lateral veins gently arch toward the tip while secondary veins throughout the leaf are pinnate.  Smaller leaves at the top of the plant are lanceolate and without broadened bases.

Woodland sunflower - Helianthus strumosusPhoto 2:  Display showing upper and lower leaf surfaces along with a lower and upper portion of a main stem.  Primary lateral veins originate off midrib at a point well within leaf blade (see arrow).

The inflorescence consists of six or so straight floral branches from an inch to about 8 inches long that grow from leaf axils from near the top of the stem.  These floral branches, which bear one or two pairs of opposite, ovate-lanceolate leaves ½ to 1 inch long (including petioles), produce about three to eight composite flower heads on ¼- to ¾-inch peduncles.  Flower heads are borne in loose clusters with about 20 to 25 total flower heads on a stem.  The central flower head of a cluster blooms prior to others in that cluster.  The period of bloom at mid-summer lasts for about a month.

Woodland sunflower - Helianthus strumosusPhoto 3:  Roughness of leaves is evident in upper leaf pair.  Small leaves near inflorescence remain opposite and retain petioles.  Involucres are composed of imbricated bracts (phyllaries) in several series.

Flower heads are composed of ray florets without stamens or pistils (sterile) and fertile disk florets that have stamens and pistils (each a perfect flower).  The surface of the central disk, before opening of florets, is covered by yellowish-green bracts (chaff) that subtend disk florets.  Flower heads, from about 1 to 3 inches across, have about 10 to 15 ray flowers with bright yellow corollas (ligules) up to 1 inch long that are strap-like and slightly infolded along the long axis.  Ray flowers encircle up to about 50 1/8-inch-long tubular disk florets with five up-pointed lobes and a truncated, constricted base.  Five closely packed stamens with purplish anthers covered with yellow pollen become exserted well above the corolla.  Thereafter, the stamens withdraw before the pistil, with a recurved bifurcated stigma, becomes exserted.  Disk florets, pollen and stigma are a pale orange.  Flower heads are subtended by an involucre composed of up to about 30 light green bracts (phyllaries) that have an elongated triangular shape with up-pointing tips and occur in several series.  The length of phyllaries is about two-times their width.

Woodland sunflower - Helianthus strumosusPhoto 4:  Floral bracts (chaff) of the receptacle are pushed aside as disk florets open.  Pollen bearing stamens are purplish.

Woodland sunflower - Helianthus strumosusPhoto 5:  Display showing phyllaries (#1), sterile ray florets (#2), fertile disk florets with dark anthers exserted (#3), fertile disk florets with exserted bifurcated stigma (#4) and bracts (chaff) that subtend florets (#5).  The needle-like appendages (arrow) will become awns on achenes.

White inferior ovaries are attached to the constricted bases of disk florets.  With fertilization, ovaries develop into dry, flattened, glabrous, dark brown, 1-seeded fruits (achenes).  Achenes have an elongated rounded base and a truncated top with two relatively long, weakly attached awns.  Seeds are spread by dropping from long, leaning stems and by foraging wildlife.

Several characteristics help distinguish Helianthus strumosus from two other widespread and very similar native woodland sunflowers, namely, Helianthus divaricatus and Helianthus hirsutusHelianthus strumosus has:  1) stems that are typically rough, but not especially hairy, 2) leaf petioles that are ¼ inch or more long with leaf blade extending onto petioles,  3) two primary lateral veins near the leaf base that originate at a point well within leaf blade, and 4) phyllaries that are about twice as long as their widths. Nevertheless, it should be admitted that even the experts often have difficulty distinguishing among these 3 species of woodland sunflower. And without the roots, even Jerusalem artichoke, Helianthus tuberosus, becomes tough to tell apart from them.

FOOTNOTE:  Woodland sunflowers are prone to naturally hybridize and species’ characteristics in hybrid plants may become muddled.

Article and photographs by ANPS member Sid Vogelpohl,

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Know Your Natives – Cut-Leaf Coneflower

Cut-leaf coneflower (Rudbeckia laciniata var. lanciniata) of the Aster (Asteraceae) family occurs across the eastern U.S. to North Dakota and New Mexico.  In Arkansas, it occurs primarily in the Ouachita and Ozark Mountains.  The genus name established by Carl Linnaeus (developed binomial nomenclature in 18th century) commemorates his professor O.O. Rudbeck.  The specific epithet relates to the slashed or torn appearance of the leaves.  Other common names include tall coneflower, goldenglow and green-headed coneflower.

This herbaceous perennial, forming clonal colonies from its rhizomatous base, is native to flood plains and moist, fertile soils in partially sunny woodlands, thickets, sloughs and prairies margins.  It does well during hot and humid summers, but quickly wilts when soil becomes dry.  Colonies have stems that reach a typical height of 5 to 8 feet but may reach 10 feet.  Light green stems are terete (rounded), slightly ridged and are glaucous (with a waxy blue-gray sheen).  The tough, non-woody stems, about ¼-inch wide, have a pulpy white interior surrounding a hollow core.  Branching occurs near the top of the plant.  Overall, the plant is glabrous, but a few fine hairs may be found.

Leaves, dark green above and lighter green below, are mostly three-lobed, but with simple leaves high in the plant.  First leaves of spring can be shallowly lobed with serrated margins.  Later, alternate stem leaves are deeply three-lobed.  Stem leaves may be 12 to 16 inches long (including 2- to 6-inch petioles) and equally wide.  The three lobes of stem leaves are narrowly to broadly lanceolate with large serrations on margins.  Lobes may be dissected to the point that some lobes, especially terminal lobes, have secondary lobes.  Width of lobes reduces gradually toward their common junction so that they may be almost sessile at the rachis.  Lateral lobes are not symmetrical along their main vein–the side away from the midrib is wider.  Leaves approaching the inflorescence become smaller and unlobed, and petioles become shorter.  Margins of the smallest leaves are entire (not serrated).  Basal and lower stem leaves tend to drop in response to drying soil.

Petioles, with grooved upper surfaces and bases that wrap halfway around the stems, support ascending leaves with drooping tips.  Narrow wings of leaf blade may extend a short way down the petiole.

Venation is slightly incised above and strongly raised below.  Primary and secondary veins are mostly aligned along the long axis of leaves and leaf lobes, while secondary and tertiary veins are pinnate to net-like (reticulate).

Cutleaf coneflower - Rudbeckia laciniata var. lanciniataPhoto 1:  A young plant in late May showing relatively shallowly three-lobed leaves.

Cutleaf coneflower - Rudbeckia laciniata var. lanciniataPhoto 2:  An established colony in mid-April.  Three-lobed leaves are further deeply cut.

Cutleaf coneflower - Rudbeckia laciniata var. lanciniataPhoto 3:  Display of various leaf shapes and a stem segment.  Upper and lower surface of large stem leaves shown.

Inflorescence, in mid-summer, consists of solitary composite flower heads on long, naked peduncles at the ends of branching stems near the top of the plant.  In the area of the inflorescence, each stem leaf subtends one smaller axillary branch.  An axillary branch may itself produce one or more leaves from which, in like pattern, other axillary branches may continue this branching pattern.  At the final leaf of a branch or stem, a peduncle bears a single flower head.  With main stems diverging away from axillary branches, the main stems within the inflorescence zigzag from leaf to leaf.

Cutleaf coneflower - Rudbeckia laciniata var. lanciniataPhoto 4:  Uppermost flower heads of a 7-foot plant in mid-July. Of the pair of heads on right, one head (left) is at the apex of a main stem and the other (right) is an axillary head.

Within the inflorescence, a single stem may produce 40 or more composite flower heads.  Flower heads, very early in their growth, are exposed as green domes surrounded by 8 to 14 elongate, pointed, outward-flaring bracts (phyllaries) of unequal length and in several series.  With approaching anthesis, ligules of the 6 to 12 infertile ray florets, at first up-pointing flare outward, become bright yellow and broadly oblong-ovate with a pinched base.  Phyllaries and ligules, at anthesis, are somewhat droopy about the central disk that is ½ inch or more wide.  The diameter of the entire flower head is to 2 to 3 inches.  The central disk remains green until the 100+ disk florets open, at which time it becomes brownish yellow.  Yellowish tubular disk florets, about ¼ inch long and 1/32 inch wide, have a tubular corolla with 5 upward pointing, triangular lobes and 5 exserted stamens.  Split (bifurcated) stigmas become exserted later than the stamens.  The central disk, appearing prickly when in bloom, becomes brown as florets fade.  Fertilized disk florets produce 1/8 inch-long, 1-seeded, 4-sided, conical-shaped achenes with short bristles at the top edge.

Cutleaf coneflower - Rudbeckia laciniata var. lanciniataPhoto 5:  A pair of nectar-feeding wasps (Scolia bicincta) eat nectar and carry pollen from flower to flower.  Stamens (red arrow) and bifurcated styles (blue arrow) become exserted as florets become receptive to pollination.

Cutleaf coneflower - Rudbeckia laciniata var. lanciniataPhoto 6:  Display of leaves from upper branches, a branch segment and front and back of flower heads.  Note that central disk of small flower head on stem is already fully exposed.

In a garden setting, cutleaf coneflower is an eye-catching plant throughout the growing season.  Its extravagant leaves and interesting flowers place it on the “list of plants for consideration” for a partially shady, large garden or natural area.  However, the plant can become a vigorous colonizer.  Some of its many extending rhizomes and offset plants will probably need to be removed every year to maintain control.  In a too-sunny or too-dry site, leaves droop and the plant may wither.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Brown-Eyed Susan

Brown-eyed Susan (Rudbeckia triloba var. triloba) of the Aster (Asteraceae) family occurs naturally in the U.S. from Texas to Nebraska and Minnesota, then east and south to the borders, as well as apparently introduced in Colorado and Utah.  In Arkansas, this species (the only variety of the species in the state) occurs primarily across the Ozark Plateaus, Arkansas Valley and Ouachita Mountains.  Other common names include thin-leaved coneflower and three-lobed coneflower.  Brown-eyed Susan, a biennial or short lived herbaceous perennial, grows in well-drained moist to wet soils in light shade to full sun within open woodlands, alluvial thickets, roadsides and prairies.  The root system includes several short taproots along with smaller roots.

Brown-eyed Susan has a primary stem that grows to 3 to 5 feet tall.  Plant width (spread) is about half as wide as the plant is tall.  Secondary ascending branches grow from the axils of most primary stem leaves, with lower branches reaching up to two feet in length.  Even with the many flowering branches, when not confined by other vegetation, the plant has an overall open to airy appearance.  Stems and branches, generally a medium green, may have reddish shading, especially when plants are younger.  Stems and branches are densely covered with upright hairs and feel very rough (scabrous).  In deer country, primary stems are eaten early in the growing season so that lower secondary branches become dominant and plants may be only a foot or two tall.

The leaves of brown-eyed Susan are variable.  All leaves are thin but, being covered with short hairs (hirsute), feel thicker and rough.  Hairs of the upper leaf surface are equally spread while on lower surfaces, hairs are concentrated on primary leaf veins.  Leaf margins and petioles have longer hairs.

In winter into spring, the reddish basal leaves vary from simple, long-petioled, and spoon shaped to three- to five-lobed.  In spring, the mounded leaves have three deeply cut, broadly rounded, irregular, finger-shaped lobes with crenulated margins.  With bolting of the primary stem, alternate stem leaves are three-lobed and may be 7 inches long and 4 inches wide, decreasing in size toward the top of the stem.  The lobed leaves at the lower portion of the primary stem transition upwards to unlobed leaves.  In deer country, three-lobed leaves may not be seen on a plant because the primary stem has been eaten.

Brown-eyed Susan -Rudbeckia triloba var. trilobaPhoto 1:  In early February, these two plants of brown-eyed Susan exhibit reddish basal leaves.  Leaf shape varies from unlobed, oval, and long-petioled to three-lobed.

Brown-eyed Susan -Rudbeckia triloba var. trilobaPhoto 2:  In early April, basal leaves are deeply cut into rounded, irregular, finger-like lobes.

The three-lobed stem leaves have a broadly lanceolate central lobe and lanceolate side lobes that are less than half the size of the central lobe.  Blades of all three lobes taper to elongated tips (attenuate) and have narrowed bases.  The spaces (sinuses) between the three lobes are elongated and rounded at the closed end.  Narrow wings of leaf blade on petioles extend partially or all the way to the stem.  Margins of leaves of these primary stem leaves vary from coarsely serrated to entire, with central lobes having more and coarser serrations.  When leaf-lobe margins are serrated, serrations occur from lobe apices to just below mid-leaf with the lower portion being entire.

Brown-eyed Susan -Rudbeckia triloba var. trilobaPhoto 3:  Leaf and stem display.  Lobes of three-lobed leaves on the primary stem are lanceolate to lanceolate-elliptic.  Simple leaves occur mainly on secondary branches and within inflorescences.  Stems are hirsute.

Unlobed leaves are normally present on secondary branches; however, they may also occur on primary stems along with smaller three-lobed and even two-lobed leaves.  Unlobed leaves have the same appearance as the central lobe of three-lobed leaves, except the smallest leaves are not serrated and are sessile.  Unlobed leaves may be 3 inches long and 1 inch wide, with size decreasing up-branch.

Flowers, on secondary branches, bloom in mid-summer over a month or more.  Branches may have several sub-branches with one or two flower-heads occurring at the end of each branch or sub-branch.  A plant in an ideal habitat with minimal competition may have hundreds of flower-heads that are evenly spread throughout.  Generally, basal leaves have disappeared by the time that the plant is in bloom.

Brown-eyed Susan -Rudbeckia triloba var. trilobaPhoto 4:  Here in a garden setting, brown-eyed Susan is on left and black-eyed Susan is on right.  Photo taken mid-June.

Brown-eyed Susan has composite flower heads, ½ to 1½ inches across, with a purplish-brown central disk composed of many very small florets surrounded by about eight sterile ray florets.  The round central disk has a stubby conical shape on an elongated receptacle.  Disk florets are each subtended, toward the outside of the disk, by a thin, acuminate, receptacular bract (chaff).  These bracts are green at first, but as the purplish-brown disk florets push out, the bracts assume the same color.  Disk florets, about one-eighth-inch long and maturing from the outside of the disk inward, are tubular with five pointed lobes.  Stamens are yellow and the pistil is purplish.  Lobes of the corolla tubes of the disk florets recurve as florets mature.

Ray florets have a yellow strap-like to ovate corolla (ligule) that first appears as a rolled-up tube.  At anthesis, ligules are linear to ovate and may have a notched tip.  Flower-heads bloom across the entire plant without any particular sequence.  Additional smaller heads may appear after the main bloom, if growing conditions remain favorable.

Brown-eyed Susan -Rudbeckia triloba var. trilobaPhoto 5:  Note stage of ray-flower development shown by the three heads.  Leaves in inflorescence are simple, hairy, sessile and lanceolate.

The flower head is based on a receptacle subtended by small lanceolate bracts (phyllaries) that form the involucre.  At anthesis, the bracts align in a single flat layer just below the ligules.  Bracts can vary from about half the length of the ligules to slightly longer than the ligules.  Bracts, the same color as the overall plant, have dense short hairs.  Fruits, about one-eighth-inch long, are dark, elongate, 1-seeded achenes that quickly mature as the seed head dries.  The persistent emptied seed heads at first look spiky due to the chaff which then falls off to reveal the receptacle.

Brown-eyed Susan -Rudbeckia triloba var. trilobaPhoto 6:  Disk florets bloom from outside edge toward center.  Involucre is composed of lanceolate bracts in a single layer.

Nine species of Rudbeckia occur in Arkansas, some with multiple varieties. Black-eyed Susan (Rudbeckia hirta), with its common name similar to that of brown-eyed Susan, may cause confusion, because the species’ disks are not quite “brown” or “black”.  Black-eyed Susan has several characteristics that distinguish it from brown-eyed Susan: 1) it prefers drier and sunnier habitats, 2) it is a smaller plant with all unlobed leaves, 3) the upper surface of leaves feels fuzzy, 4) a single flower-head terminates each long secondary stem, and 5) the involucre has several layers of bracts.

Black-eyed Susan -Rudbeckia hirtaPhoto 7:  Basal leaves of black-eyed Susan in late March.  Note underlying over-winter leaves of this biennial.

Brown-eyed Susan -Rudbeckia triloba var. trilobaPhoto 8:  Four flower-heads of brown-eyed Susan at lower-left and four heads of black-eyed Susan at upper-right.  Texture of central disks differs between species, but color is about the same.  Note difference of involucres.

In a home landscape, brown-eyed Susan would work well in a naturalized setting where its tall lanky growth habit would fit in.  For a more tidy plant, the shorter more compact black-eyed Susan (which typically has flowers for two years) would probably be a better option.  Both species self-seed.

Footnote:  Orange coneflower (Rudbeckia fulgida) has flowers similar to black-eyed Susan.  This perennial species forms colonies from rhizomes and has broad, mostly basal leaves.

Article and photographs by ANPS member Sid Vogelpohl

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Fall 2016 Meeting Update and Latest Claytonia now available

Dear ANPS Member,

We wanted to share with you the latest news on the Fall 2016 Meeting coming up next month in Mena, Arkansas, and tell you that the Fall 2016 Claytonia newsletter is now available for downloading!

The fall 2016 Claytonia newsletter has been published and the mailed copies will go out around August 8 or 9.

Click here to download and read the Fall 2016 Claytonia.

Click here for all the details on the Fall 2016 Meeting in Mena, Arkansas, to be held September 23-25.

Meeting details:

Everybody is welcome to attend! Meeting registration is only $5 with no pre-registration required. Registration will begin at 5:00PM on Friday, September 23d.

Meeting Location: Ouachita Center on the Rich Mountain Community College Campus (look for ANPS signs as the Ouachita Center is too new to be on their campus map!)

Directions from Sun Country Inn to Rich Mountain Community College

Hotel: Sun Country Inn, 1309 Hwy 71 North, Mena, AR  71953

Phone: (479) 394-7477 or 877-394-7477

UPDATE: As of August 29, 2016, Sun Country Inn is fully booked. An alternative is Rainey Day Resort in Mena. Click here for more info about Rainey Day Resort.

Directions from Hot Springs to hotel (about 1 1/2 hours).

Directions from Russellville to hotel (about 2 hours).

Twenty-five rooms (15 double queens and 10 kings) have been reserved at the reduced rate of $84.55 plus tax per night. Reservations must be received by August 23, 2016 to guarantee the reduced rate. Be sure to mention that you are with the Arkansas Native Plant Society when making your reservation.

Dining Options: We will have a Potluck meal Friday and Saturday evenings. Bring a dish or just come and eat! There are also many dining options in downtown Mena (Stache’s Cookery (tasty), Branding Iron, American Artisans (awesome lunch!), Chopping Block Steakhouse, and Skyline Cafe (breakfast is early and delicious!))

Field trips: Several field trips to local areas of top botanical interest will be scheduled for Saturday 8:00 AM-5:00PM and Sunday 8:00AM-12:00PM:

Queen Wilhelmina State Park on Rich Mountain

Cossatot River State Park south of Mena

Ouachita National Forest in the vicinity of Mena

There will also be an opportunity Saturday afternoon to stay cool inside and watch Catherine Zimmerman’s Hometown Habitat: Stories of Bringing Nature Home featuring Doug Tallamy and many others dedicated to creating native landscapes across the country.

We will offer something for everybody, whether you want to take it slow and easy or something more vigorous. You must sign up for field trips on Friday evening to allow for adequate logistical planning.


Friday 7:00PM – The annual Native Plant Auction (bring plants or books or homemade jelly to auction off!)

Saturday 7:00PM – Dr. Travis Marsico –  Associate botany professor and curator of the Arkansas State University Herbarium will give a presentation on the digitization of Arkansas herbaria and how ANPS members can help.

Saturday 7:45 – Dwayne Estes – Associate professor at Austin Peay State University (APSU), curator of APSU Herbarium, and Botanical Explorer with Botanical Research Institute of Texas (BRIT) will speak on the fascinating similarities between the vegetation in the Ouachita Mountains and the Cumberland Plateau of Tennessee.

For complete and up-to-date details, go to or contact Virginia McDaniel,, (828) 545-2062.

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Know Your Natives – Joe Pye Weed

Joe Pye weed (Eutrochium purpureum*) of the Aster (Asteraceae) family occurs in the U.S. from Louisiana and Oklahoma, north to South Dakota and Minnesota, thence east and south to the borders.  In Arkansas, this species occurs in the Ozark and Ouachita Mountains, higher elevations of the Arkansas River Valley, and on Crowley’s Ridge.  Previously, this species was classified as Eupatorium purpureum, a name still recognized by some authors.  (Such botanists are known in the trade as “lumpers”.) Preferred habitat includes prairies, woodlands, thickets and stream margins with mesic soil and partial to full sunlight.  Other common names include sweet-scented Joe Pye weed, green-stemmed Joe Pye weed, and kidney root.  These common names, respectively, are based on a pleasant scent from flowers and crushed leaves, on stems that are mostly green, and on the plant’s roots having been used to treat kidney stones.  For a link to a review of the name “Joe Pye”, see footnote.

Joe Pye weed is an herbaceous, clumping, erect perennial.  Stout main stems, that may reach 7 feet tall, grow in tight clumps.  Lateral stems arise from the uppermost leaf axils of main stems.  Main stems and lateral stems are green except for dark purple shading at the base of petioles and on stem nodes.  The entire plant is mostly glabrous (hairless).  The upright stems, as the growing season progresses, often lean outward from the plant’s main axis, but remain mostly erect.  The root system is shallow and fibrous.

Joe Pye Weed - Eutrochium purpureumPhoto 1:  In mid-March, new shoots emerge showing whorled leaves on purple nodes.

Leaves grow from swollen nodes that are uniformly and widely spaced along half-inch-diameter terete main stems.  Leaves, up to 10 inches long and 3 inches wide, occur in whorls of three to five, with four being typical.  The largest main-stem leaves, on the lower two-thirds of the plant, have margins that are entire near the base and coarsely serrated beyond.  Leaf blades gradually taper to an elongated tip (acuminate tip). Leaf blades taper quickly toward the base and then become wing-like onto the petiole.  Whorled leaves on the upper third of the plant quickly decrease in size and become lanceolate with lightly serrated margins and short petioles.  Leaves, somewhat crinkled throughout the plant, are a dark dull green above and a lighter dull green below.  Pinnate veins are recessed above and raised below.

Joe Pye Weed - Eutrochium purpureumPhoto 2:  Display showing upper and lower surfaces of whorled leaves along with much smaller leaves in a compound panicle.  A glabrous stem and leaf node are also shown.

Joe Pye Weed - Eutrochium purpureumPhoto 3:  Along with the terminal inflorescence, lateral secondary stems also produce inflorescences.  Photo taken in late May.

Inflorescences are restricted to the upper one-fifth of main stems.  In early summer, pale pinkish to purplish flower heads are produced in large, loose, convex-topped, compound panicles at the ends of a terminal stem and a number of lateral stems.    The uppermost group of compound panicles has a central stem growing straight up from the center of the uppermost leaf whorl along with lateral stems growing from leaf axils.  At several lower whorled-leaf nodes, some or all leaf axils may produce panicles on lateral stems.  Lateral stems, up to about 2 inches long, of the uppermost group of panicles and of lower panicles are positioned about 50 degrees off the main stem.

Joe Pye Weed - Eutrochium purpureumPhoto 4:  A plant in full bloom in early July.

A compound panicle may be composed of several to about five individual panicles.  Small lanceolate leaves occur at the base of the lowest panicles and additional smaller bracteal leaves may occur within compound panicles.  A panicle may bear 50 or more separate flower heads so that the uppermost group of panicles may have 250 or more flower heads.

Each elongate, tubular flower head, about one-half inch long and one-sixteenth inch wide, bears up to about six disk florets on very short thin pedicels.  Florets of each head are enclosed by an elongate involucre composed of appressed linear bracts (phyllaries) of differing lengths.  Florets have five flared, triangular lobes.  A long, deeply split, white, thin and twisting style (bifurcated style) is prominently exserted while stamens are hidden (inserted).  The corolla, attached directly to the upper end of an elongate ovary, is surrounded by a pappus of numerous fine bristles appressed to the corolla tube.  Like the corolla, the pappus (morphologically a highly specialized calyx) is attached to the top of the ovary.  (There are no ray florets.)

Joe Pye Weed - Eutrochium purpureumPhoto 5:  Bifurcated styles are strongly exerted from tubular florets enclosed by linear phyllaries.   Butterfly is a Northern Cloudywing (Thorybes pylades).

At maturity and fertilization, each ovary enlarges and hardens to become an elongate achene with fine bristles at its top (i.e., the pappus).  With drying, the bristles fluff up, allowing the 0ne-seeded achenes to be dispersed by wind.

Joe Pye Weed - Eutrochium purpureumPhoto 6:  In late July, stems remain leafy and erect as achenes dry for wind dispersal. Yellow flower and leaves in background is cutleaf coneflower (Rudbeckia laciniata)

For a larger wildflower garden or naturalized area, Joe Pye weed may be appropriate.  It may add significant structure and texture with its large, uncrowded, whorled leaves on tall stems.  It has showy flowers.  The number of stems increases from year to year, but these remain in a tight clump.

*  Two varieties of Joe Pye weed (E. purpureum var. purpureum and E. purpureum var. holzingeri) are believed to occur in Arkansas.  They are separated by leaf undersurface pubescence: var. purpureum is glabrous or sparsely hairy along veins; var. holzingeri is densely and evenly hairy.  However, inventories in the state have not traditionally separated them, so their ranges are still obscure.  A second species of Eutrochium in Arkansas is hollow-stemmed Joe Pye weed (E. fistulosum) which has 4 to 7 leaves per whorl and hollow stems that are purple to purplish with a bluish-white powdery bloom.  It occurs along streams, in bottomland forests, or in marshes.

Footnote:  For review of the name “Joe Pye”, see:

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – American Germander

American germander (Teucrium canadense var. canadense) of the Mint (Lamiaceae) family occurs across the eastern half of the U.S.  In Arkansas, it is found statewide.  Also known as wood sage and Canada germander, this is the only species of the genus known in Arkansas.  The genus is believed named in honor of the first king of Troy (Teucer) for species found in the Mediterranean area.  The specific epithet is in reference to this species being originally described from Canada.  It is native to moist soils in low areas of woods, thickets, marshes and prairies with full or partial sunlight.

This herbaceous perennial, with erect stems that grow from rhizomes, has hollow square stems.  Main stems, which may have small axillary branches on the upper portion of the plant and undeveloped branches lower, grow to 3 feet tall.  Colonies readily form from the rhizomes.

Simple, opposite leaves, with a blade up to 4 inches long and 1¾ inches wide on a petiole up to ½ inch long, are broadly lanceolate with toothed margins.  The upper (adaxial) leaf surface is a slightly glossy dark green while the lower (abaxial) surface is a lighter dull green.  Leaf pairs are decussate (rotated 90 degrees from one pair to the next).  Pinnate leaf veins are recessed on upper surface and raised on lower surface.  Primary veins arc toward the leaf apex, with extremities becoming parallel to the leaf margin.  Leaves, from mid-leaf, are gently tapered to the tip while the taper to the rounded leaf base is more abrupt.  Leaf-blade tissue extends a short distance onto the petiole.

American germander - Teucrium canadense var canadensePhoto 1:  New growth of American germander from rhizome.

American germander - Teucrium canadense var canadensePhoto 2:  Axillary branches occur along upper portion of stem.  Note also the glossy dark green upper leaf surfaces and recessed veins.

The inflorescences, with a month-long bloom beginning about mid-June, consist of terminal racemes to 8 inches long with flowers crowded together.  Axillary branches, near top of main stem, may also produce short racemes.  Single, persistent leaves (bracts) subtend each flower, with bract size decreasing to the apex of raceme.  Blooming may be interrupted and plants wilt if soil becomes dry, but plants revive and blooming continues with better moisture.

Flowers, when viewed from the side, are about ½ inch long (including the calyx) and ½ inch tall with green, bell-shaped calyxes on short pedicels.  Calyxes, horizontal to ascending along the rachis, have three small, broadly triangular upper teeth and two small, broader triangular lower teeth.

American germander - Teucrium canadense var canadensePhoto 3:  Note size of leafy bracts subtending each flower and axillary branch at base of raceme to left.  Photo: Mid-June.

Flowers open from the base of a raceme to the apex in sequential fashion.  The corolla is white to light lavender with purple striations and spots on the lower lobe.  The trough-shaped descending corolla seems to have “rolled” out of the calyx.  The corolla has five lobes: an upper pair of pointed lateral lobes, a middle pair of rounded lateral lobes, and a single significantly larger spoon-shaped lower lobe.  In side profile, the lower margin of the corolla arches smoothly downward from the calyx to the beginning of the lower lobe from which point the lower lobe drops directly down and backward.  In side profile, the upper margin’s downward trend is interrupted by the up-pointing upper lobes, followed by the out-pointing middle lobes and the downcast lower lobe.  Flowers have two pairs of stamens of unequal length with reddish anthers and a pistil with a split stigma.  Stamens and the style and stigma are of equal length and arch above the corolla to terminate well above the lower lobe.  Filaments of the stamens and the style and stigma have a greenish-white color.

American germander - Teucrium canadense var canadensePhoto 4:  Lower lobes of flowers are marked by purple striations and spots.

American germander - Teucrium canadense var canadensePhoto 5:  Display showing a flower in bud (See #1), three flowers at anthesis (See #2), a flower in decline (See #3) and a calyx bearing developing seed (See #4).

With pollination and fertilization, flowers produce four round, tawny, one-seeded nutlets.  Nutlets are held within the persistent calyx until, with drying, they are loosed and dispersed.

American germander may be confused with some of the superficially similar hedge-nettles (genus Stachys), also of the Mint (Lamiaceae) family.  Ouachita hedge-nettle (Stachys iltisii) can be especially confusing.  This hedge-nettle occurs primarily in the Ouachita Mountains of Arkansas and Oklahoma, with a few scattered occurrences also in the Arkansas Valley and Ozark Mountains of Arkansas.  Like germander, it forms rhizomatous colonies, sometimes in similar habitats.  However, Ouachita hedge-nettle can be distinguished by the following: 1) very dense short hairs on upper and lower leaf surfaces as well as on stems, 2) a tapered leaf base, 3) flowers that are arranged in tiers, 4) generally blooming a month earlier, 4) a hood-like upper corolla-lobe and 5) straight lavender to purple filaments and style and stigma that do not project beyond the upper lobe.

American germander - Teucrium canadense var canadense and Ouachita Hedgenettle - Stachy iltissiPhoto 6:  Comparative display of leaves and stems; Ouachita hedge-nettle on left and American germander on right.

Ouachita hedgenettle - Stachys iltisiiPhoto 7:  Flowers of Ouachita hedge-nettle, arranged in tiers, are more strongly colored.  Upper lobe projects over stamens and pistil. (Note: Pair of leaves below flowers is not Ouachita hedge-nettle.)

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Net-leaf Leather-flower

Net-leaf leather-flower (Clematis reticulata*) of the Buttercup (Ranunculaceae) family is a perennial herbaceous vine found in portions of the Southeastern U.S from eastern Texas and Oklahoma to South Carolina and Florida.  In Arkansas, the species is recorded from north-central and southwestern parts of the state.  It is found in mesic to dry, sandy to rocky soils of open upland woodlands and thickets.  Nomenclaturally, Clematis derives from the Greek word for climbing or vining plants.  The specific epithet is from the Latin word meaning “netted,” and relates to the pattern of the plant’s prominent leaf veins.

A mature net-leaf leather-flower plant produces one to several fast growing vines (stems) from a deeply set, fleshy, stubby root.  Stems grow upright for several feet.  Fascinating (unique?) tendril-like stalks of the leaves and especially the leaflets coil around and latch onto surrounding twigs as the vines grow more or less upward depending on support.  When support is lacking, stems ramble over and through themselves and other vegetation so that the plant becomes well anchored.  Stems, glabrous and round with minor ridges and up to 12+ feet long, become reddish and somewhat woody early on.  Dead stems often remain into the next growing season but new growth arises from the roots.

Leaves are opposite and vary from simple to mostly compound.  The lowest leaf pairs of young plants are simple, followed by pairs of three-lobed leaves, followed by pairs of odd-pinnate compound leaves with simple leaflets.

Principal leaves are odd-pinnate to a foot or more long and equally wide, with leaflets typically bearing secondary leaflets to become twice compound.  Distal rachises and petiolules (leaflet stalks) become long and twisted and can become especially tendril-like by abortion of their leaflet blades.  Shape of leaflets varies, with smaller leaflets being ovate to elliptic while larger leaflets are two-lobed (mitten-shaped) or three-lobed with the central lobe largest.  Reticulate (net-like) veins are incised on the adaxial (upper) side and raised on the abaxial (lower) side.  Leaflets, a dull medium green adaxially and light green abaxially, are leathery.  Larger leaflets may be 3+ inches long and 2+ inches wide.  Leaf and leaflet size decrease toward the extremities of the plant.

Netleaf leatherflower - Clematis reticulataPhoto 1:  Lowest leaves of this young plant are simple (arrow), leaves of the next higher pair are three-lobed, and upper leaves are odd-pinnate with simple leaflets.  Photo taken April 21st.

Netleaf leatherflower - Clematis reticulataPhoto 2:  Display of a typical twisted leaf from a mature plant (cut and flattened).  Note variation of leaflet shape and coiled leaflet stalk (see arrow).  Leaf about 1 foot long.

Early (lower) inflorescences consist of single flowers on long ascending pedicels growing directly from leaf axils of main stems.  Higher on plants, short axillary branches may produce clusters of flowers on short ascending pedicels.  Typically, pedicels have a pair of small simple leaves in their lower third.  Almost all leaf axils, regardless of leaf size or position on plant, produce rudimentary flower buds, but many buds do not develop fully.

Netleaf leatherflower - Clematis reticulataPhoto 3:  Flower buds growing on pedicels from leaf axils of the somewhat woody primary stem.  In photo, stem is hanging downward so that secondary stems with flower buds twist up from “below” leaf axils.

Ascending pedicels bend sharply downward at their upper end so that the plant’s bell-shaped (campanulate) flowers point downward.  Flowers have four thick, straight-edged sepals (no petals) which are widest at the pedicels then narrow sharply to an acute tip–thus buds are sharply pointed.  Sepals have a central rib, especially prominent near the pedicel, that extends to the tip.  Lesser ribs align with the sepals’ edges which are tightly pressed together.  Sepal color near the pedicel is a dark purple to pale lavender which fades into white and then light green at the tip.  Sepals are whitish to greenish on the inside.  As flowers reach anthesis, tips of sepals recurve to expose the ends of tightly clustered stamens that tightly surround styles and stigmas of a tight cluster of pistils.  Stamens, narrowly linear, have white filaments covered with minute white hairs with elongate, similarly colored hairy anthers.

Netleaf leatherflower - Clematis reticulataPhoto 4:  A flower, lower on plant, held high by long pedicel (arrow).  Note ridged sepals, reddish stems and reticulated leaf veins.

Netleaf leatherflower - Clematis reticulataPhoto 5:  Display showing a flower with sepals removed (lower left) and a flower with sepals and stamens removed (left center).  Removed stamens positioned at right and style and stigma of a single pistil (ovary removed) is to the left (arrow).  Note hairs on pistil.

With flower maturity, sepals and stamens are discarded so that previously mostly hidden white pistils with their white ovaries become prominent on a naked receptacle.  Styles enlarge as the ovaries mature and white hairs found along one side of the styles elongate so that, with maturity of the seed-like fruits (1-seeded achenes), each flattened, rounded, beaked achene has a persistent plumose “tail.”  Achenes and tails form a round, airy “seed”- or fruiting-cluster, several inches in diameter, that is persistent into spring, unless dispersed by wind or wildlife.

Netleaf leatherflower - Clematis reticulataPhoto 6:  Fruiting clusters: Achenes are now fully plumed with persistent styles.  Photo taken November 25th.

Net-leaf leather-flower is a well-behaved vine that should find favor in a garden setting.  It will do well in most upland soils in partial shade with average moisture.  Once established, it is drought resistant.  With persistent seed clusters, it is a year-round attraction.  Beware though, stems growing along the ground are tough enough to trip a person.

Five other species of leather-flower have been reported from Arkansas; namely, swamp leather-flower (C. crispa), white-leaf leather-flower (C. glaucophylla), Pitcher’s leather-flower (C. pitcher), pale leather-flower (C. versicolor), and vase-vine (C. viorna).  Characteristics of C. reticulata that help in its identification include habitat, reticulated leaf veins, flower color and flower shape.  Three additional species of Clematis are also known from Arkansas (two native [C. catesbyana and C. virginiana] and one introduced [C. terniflora]), but these are true woody vines that have abundant clusters of small white flowers, bloom in late summer/fall, and are generally referred to by the common name “virgin’s-bower.”

*The Clematis reticulata “complex” is currently under revision by Dwayne Estes (Austin Peay State University & Botanical Research Institute of Texas) and collaborators, including Theo Witsell (Arkansas Natural Heritage Commission).  In Arkansas, the complex is expected to be split into at least several additional species.

Article and photographs by ANPS member Sid Vogelpohl

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Fall 2016 Meeting Information

Arkansas Native Plant Society
2016 Fall Meeting
September 23-25

Rich Mountain Community College
(look for the ANPS sign!)
Ouachita Center
Mena, Arkansas

Everybody is welcome to attend! Meeting registration is only $5 with no pre-registration required. Registration will begin at 5:00PM on Friday, September 23.

We have reserved a block of rooms at the Sun Country Inn ($84.95 + tax per night). All rooms reserved under “Arkansas Native Plant Society”. Twenty-five rooms (15 double queens and 10 kings) have been reserved at the reduced rate of $84.55 plus tax per night. Reservations must be received by August 23, 2016 to guarantee the reduced rate. Be sure to mention that you are with the Arkansas Native Plant Society when making your reservation.

UPDATE: As of August 29, 2016, Sun Country Inn is fully booked. An alternative is Rainey Day Resort in Mena. Click here for more info about Rainey Day Resort.

Some driving directions to help you get to the hotel in Mena and from the hotel to the meeting location:

Field trips: Several field trips to local areas of top botanical interest will be scheduled for Saturday 8:00 AM-5:00PM and Sunday 8:00AM-12:00PM. We will offer something for everybody, whether you want to take it slow and easy or something more vigorous. You must sign up for field trips on Friday evening to allow for adequate logistical planning.

Queen Wilhelmina State Park on Rich Mountain

Cossatot River State Park-Natural Area south of Mena

Ouachita National Forest in the vicinity of Mena

Some field trips will be repeated on Sunday morning to accommodate those who could not work them into their schedule for Saturday.

The annual native plant auction on Friday night is an event not to be missed. It starts at 7:00PM and continues until the plants are gone! It’s not too early to be thinking about and preparing the plants you want to contribute to the auction.

There will also be an opportunity Saturday afternoon to stay cool inside and watch Catherine Zimmerman’s Hometown Habitat: Stories of Bringing Nature Home featuring Doug Tallamy and many others dedicated to creating native landscapes across the country.

Dining Options: Potluck meal Friday and Saturday evenings. Bring a dish or just come and eat! There are also many dining options in downtown Mena: Stache’s Cookery (tasty), Branding Iron, American Artisans (awesome lunch!), Chopping Block Steakhouse, and Skyline Cafe (breakfast is early and delicious!).

We have two incredible speakers on tap for Saturday evening.

The first at 7:00PM is Dr. Travis Marsico – Associate Professor and curator of the Arkansas State University Herbarium. He will give a presentation on the digitization of Arkansas herbaria and how ANPS members can help.

Next at 7:45 PM is Dr. Dwayne Estes – Associate Professor at Austin Peay State University, curator of APSU Herbarium, and Botanical Explorer with Botanical Research Institute of Texas (BRIT). He will speak on the fascinating similarities between the vegetation in the Ouachita Mountains and the Cumberland Plateau of Tennessee.

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Know Your Natives – Carolina Rose

Carolina rose (Rosa carolina) of the Rose (Rosaceae) family occurs in the U.S. from Texas to Nebraska to Minnesota thence east and south to the borders.  In Arkansas it occurs throughout the state.  The genus name is Latin for “rose.”  The specific epithet refers to the type location for the species–i.e., the specimen based on which this species was first described and named was collected in the Carolinas.  Other common names include “pasture rose” or “low rose.”  Habitats include woods and thickets as well as prairies and glades with various dry to mesic soils.  It does well in partial shade or full sun.

This perennial, low-growing deciduous shrub has a tap root and shallow horizontal rhizomes.  Plants, 1 to 3 feet tall, have erect woody stems and branches.  New branches, from several to 6 inches long, are a light green the first year, become reddish brown the second year, and dark tan in following years.  All stems and branches are covered with many fine to slender straight prickles intermixed with a few significantly larger and stouter prickles which occur mostly near leaf nodes.  The numerous prickles, set perpendicular to stems and branches, are persistent with the larger ones reaching ½ inch.

Alternate leaves are odd-pinnate-compound generally with five elliptic leaflets; however, three and seven leaflets also occur.  Leaflets taper toward their apices and bases.  The upper three-fourths of leaflet margins are serrated, with serrations becoming smaller toward the base where they are absent.  The hairless (glabrous) leaflets are glossy dark green above and non-glossy lighter green below.  Leaves up to 5 inches long, including an inch-long petiole (stalk of leaf), have terminal leaflets up to 1½ inches long, including a ¾ inch petiolule (stalk of leaflet).  Lateral leaflets are on very short petiolules.  The upper leaflet pair is of similar size as the terminal leaflet while lower pairs decrease in size toward leaf base.  Leaf rachis, when viewed from the side, has a smooth arch from the base of petiole to the base of petiolule of the terminal leaflet where a “knee” flexes the terminal leaflet upward.  The lower side of rachis is covered with small prickles which continue along lower side of leaflets’ mid-ribs.  The upper side of the rachis is grooved.  Narrow, elongate stipules, which terminate with acute spreading tips, are attached along the bases of petioles.  A single “extra” leaflet may occur at the upper end of a stipule.  Margins of stipules are entire or have minute prickles.

The inflorescences occur at the ends of current year’s branches, and typically consist of a single flower, but two flowers may also occur.  A calyx consists of five light green, strap-like to narrowly triangular sepals which terminate with long, narrow to leafy tips.  Pedicels (flower stalks) are covered by glandular hairs which extend onto the sepals.  A prominent ball-shaped, smooth hypanthium (which will be the hip in fruit) is located at the base of the calyx.

Carolina rose - Rosa carolinaPhoto 1:  Characteristic leaves, stipules and sepals (with elongated tips) are shown along with a flower bud above and a flower past bloom below.

Carolina rose - Rosa carolinaPhoto 2:  At bloom, calyx and petals become flattened so that pollen and pistils are well exposed to insects.  Terminal leaflets are flexed upward by a “knee” in the rachis.

Inflorescence occurs in May.  Flowers normally are in bloom for only one day, with the blooming period of a colony extending over several weeks.  Flowers are two or more inches across with five light to dark pink petals and a wide mass of pistils.  Petals are wide, slightly overlapped with a broad gently notched tip.  Numerous stamens with white filaments radiate from the base of the pistils so that the showy yellow anthers are spaced a distance out from the pistils.  Anthers become brown as flowers mature.

Carolina rose - Rosa carolinaPhoto 3:  Display of stem, front and back of leaves, and flowers.  Note “extra” leaflet at upper end of stipules.  (Catkin of hickory flowers caught on prickles of stem.)

After bloom, the hypanthium develops into a bright red, smooth, fleshy berry-like fruit (hip) that contains about 10 hard achenes (technically the true fruits, each with a single seed within) around a central axis.  Hips remain on the shrub into the following spring, unless eaten by wildlife.  In spring, remaining hips become dry, eventually deteriorating to release achenes.  Mature achenes are somewhat elongated, shiny, smooth and chestnut-brown with two flattened sides and one curved side.  Upper ends of achenes are covered with short hairs.

Carolina rose - Rosa carolinaPhoto 4:  Berry-like rose hips and 1-seeded achenes in spring from previous year’s flowers.

Carolina rose would do well in a garden or naturalized area in loose, dry to moist soils where the plant’s tendency to form colonies may be welcomed.  It’s a good choice where soil erosion is an issue.  Flowers have a very pleasant rose scent.  Once established it will do well in sun and will be drought tolerant.  Flowers produce pollen for bees, but do not produce nectar.  Spiny Rose Gall Wasps (Diplolepis bicolor) can deposit eggs at base of new branches sometimes causing the plant to produce half-inch galls with several larvae at the center.

Carolina rose - Rosa carolinaPhoto 5:  Spiny galls provide protection for larvae of Spiny Rose Gall Wasps.

Three other native rose species are found in Arkansas; namely, white prairie rose (Rosa foliolosa), uncommon and known only from a couple localities in the Ouachita Mountains; swamp rose (Rosa palustris), which grows in wetlands and is known only from the northeastern corner of the state; and climbing rose (Rosa setigera), which occurs throughout much of the state but less frequently in the West Gulf Coastal and Mississippi Alluvial Plains.  At least six non-native species also occur as naturalized in Arkansas.  The most widespread and invasive non-native is multiflora rose (Rosa multiflora), which spreads by tip-rooting of stems and by freely seeding from its many white flowers.  Carolina rose can be identified by a combination of its short stature, straight prickles, colonial nature, and wide mass of pistils.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Red-Ring Milkweed

Red-ring milkweed (Asclepias variegata) of the Dogbane (Apocynaceae) family, formerly of the Milkweed (Asclepiadaceae) family, occurs in the U.S. from eastern Texas and Oklahoma to Illinois and east and south to the borders.  It occurs throughout much of Arkansas except for small areas in northwest and east-central parts of the state.  The genus name commemorates Asklepios, Greek god of healing and medicine.  The specific epithet denotes the variegated flowers, specifically, a white flower that typically has a reddish ring.  Another common name for this plant is “white milkweed”.  Thirteen additional species in the Asclepias genus occur in Arkansas.

This perennial plant thrives in dry to moist, loamy to rocky open woodlands and edges of woodlands as well as sunny glades.  Plant numbers in an area are generally low, with each plant typically isolated from others.  All leaves and a terminal flower cluster are apparent soon after a stem appears in early spring.  The 3-foot tall, smooth and unbranched stems bear 5 to 7 opposite, widely spaced large upper leaves as well as several pairs of smaller lower leaves which drop early.  Stems, petioles and main leaf veins are reddish in spring but become more green during the growing season.  As typical for most species of milkweeds, stems and leaves of red-ring milkweed, which are mostly glabrous (hairless), contain white sap.

Red Wing Milkweed - Asclepias variegataPhoto 1:  New stems appear in early spring with the developing inflorescence already visible at top.  Photo taken in mid-April.

Oval to oblong leaves, large relative to plant height, are up to 6 inches long and 3 inches wide with smooth margins and 1-inch petioles.  Leaf margins are slightly wavy with a broadly rounded apex with an abrupt short tip.  Leaves have a broadly rounded to gently tapered base, and leaf blades are mostly flat, facing sunlight.  Leaves, which appear slightly waxy and feel leathery, are medium green above and lighter green below.  Principal veins off midrib, almost perpendicular to the midrib, are prominent and widely spaced.

The inflorescence, in the form of several umbels along the growing stem, begins immediately above the upper pair of large leaves.  Umbels, tightly clustered at first, become separated as the plant grows.  The first umbel is produced at a node bearing a pair of large leaves. From this point, the stem continues with several additional umbels from nodes with greatly reduced leaves.  Small linear bracts occur at the base of umbels which fade as flowers open.

Umbels, with 15 to 30 flowers on light green, short pedicels, are round-topped and held upright.  Flowers may be loosely to tightly spaced depending on plant’s age and habitat.  When umbels first become discernible, a loose calyx composed of five light green lobes can be seen surrounding tiny light green flower buds.  As flower buds enlarge, they change from light green to white and the calyx becomes hidden.  Tops of flower buds are pinkish with a star pattern where petals meet.  At bloom, umbels may be up to 3 inches across on peduncles up to 1 inch long.  Flowers are up to ½ inch wide and on pedicels about ½ inch long.

Red Wing Milkweed - Asclepias variegataPhoto 2:  Four umbels are shown with the least developed one being sited at the end of the growing stem.   Calyxes, especially noticeable on the least developed cluster, become hidden as flower buds enlarge.

Red Wing Milkweed - Asclepias variegataPhoto 3:  Elevated hoods and horns cause foraging insects to inadvertently place their feet into stigmatic slits.  Photo taken in mid-May.

Milkweeds have unusual flower morphology and a complex pollination process.  A red-ring milkweed flower has a corolla composed of five reflexed white lobes, a corona composed of five white elevated hoods (nectar chambers) with exserted, inward-pointing white horns and a short, unique central structure, the gynostegium.  The gynostegium consists of the staminate and pistillate parts of the flower fused together. It bears five stigmatic grooves or slits through which pollen can come into contact with receptive areas of the true stigma. Fused stamen filaments form a tube, the column, that surrounds the lower portion of the gynostegium.  The upper portion of the gynostegium contains five anthers, each with two chambers, in which the pollen grains are cemented into masses called pollinia.  Adjacent pollinia (from adjacent anthers rather than from the same anther) are connected to a “clip” via wiry connecting arms (translator arms).  Five clips are positioned at the tops of the five stigmatic slits, between the hoods.  Two ovaries are found within the column at the base of the gynostegium.  For successful pollination to occur, a clip with its attached pair of pollinia is accidentally jerked out by a foraging insect.  Subsequently, the insect inadvertently inserts one of the two pollinia into the stigmatic slit of a second flower.  The pollen grains in the pollinium then grow tubes to the 100 or so ovules in one ovary whereby seeds are produced.*  A typical red-wing milkweed can produce a hundred or more flowers in several umbels, but generally few pods develop on a plant.

Red Wing Milkweed - Asclepias variegataPhoto 4:  The last umbel is in bloom on this stem.  Note that flowers of lower umbels have fallen to expose stubby peduncle tips.  Seed pods have not developed on the exposed peduncles.  Photo taken in early June.

Seed pods are slender and erect with a length of 4 to 5 inches and width of ¾ inch.  When mature and dry, pods split along a seam which exposes enclosed flat, circular and overlapping seeds.  Seeds have white, silky, filament-like hairs that fill the remainder of the pod.  Exposed hairs become fluffy in drying wind and sun.  The wind pulls the seeds out of pods one-by-one for nearby or long-range dispersal.

Red Wing Milkweed - Asclepias variegataPhoto 5:  These immature seed pods show the characteristic shape of red-ring milkweed pods.  Photo taken in mid-August.

In partially shaded gardens, red-ring milkweed would be a “stand-out” plant that is well-behaved.  With its large simple leaves with highlighted veins and showy flowers, it has pronounced structure.  The writer has observed that red-ring milkweed, in comparison to some other native species, is not a favored host plant of monarch butterfly caterpillars, and also that it does not appear to be heavily preferred by deer.

  • *Pollen tubes grow out of pollen grains from the convex edge of a pollinium.  A flower cannot self-pollinate.  An insect must accidentally insert a pollinium into a narrow but empty stigmatic groove.  The translator arms are critical in getting the pollinium properly oriented for insertion: they rotate 90 degrees as they dry, bringing the sharp, convex edge of the pollinium (rather than the broad flat surface) to a position that allows “easy” insertion into the groove.

Article and photographs by ANPS member Sid Vogelpohl

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