Know Your Natives – Wild Strawberry

Wild Strawberry (Fragaria virginiana) is an evergreen plant which produces scarlet strawberries* with achenes embedded in pits. The genus name derives from the Latin word “fragum” in reference to the fragrance of mature strawberries. The specific epithet refers to the state from which the species was originally collected and described. The common name probably originates from the word “strew” in reference to the tangle of ground-hugging stems. In the eastern U.S., Wild Strawberry occurs in a large area roughly bounded by a line from North Dakota to Maine (extending into Alberta and Newfoundland, Canada), along the Atlantic Coast to the Florida Panhandle, across to eastern Texas and back to North Dakota. Also, it occurs in large disjunct areas of western U.S. In Arkansas, it occurs in the Ozark Plateaus, River Valley and Ouachita Mountains, along with widely scattered occurrences in the Gulf Coastal and Mississippi Alluvial Plains. Other common names include Common Strawberry, Scarlet Strawberry and Virginia Strawberry. Habitats include dry to mesic soils in sunny to partially shaded sites such as prairies, woodland borders, glades and rights-of-way. Some authorities have divided this species into various subspecies or varieties.**

Related to the cultivated strawberry***, Wild Strawberry is a low-growing, herbaceous, colonial species with stoloniferous stems. Stems appear at the same time as the inflorescence in mid-spring and continue to grow into late-spring. The several, ground-hugging stems of a mature plant radiate from the parent plant as they maneuver through their surroundings, often lodging in crevices. The slender, rather limp (but tough) stems (to 3 feet long) have widely spaced nodes bearing bracts, leafy bracts and leaves – – stems otherwise naked. Stems, terete along their internodes, have dense spreading (set at 90⁰ to stem) pubescence. The first node (which may be 1+ foot from the parent plant) may produce a secondary stem which may develop in the same manner as a primary stem. As stems elongate to their second node (then at stem tip), the node is bent down to the soil. New leaves rise at the node and roots anchor a new plantlet. As the stem lengthens with additional nodes, those nodes that may produce a secondary stem alternate with nodes that bear plantlets. The internode segments between two “plantlet nodes” arch above the soil so that any secondary stems are elevated and the next plantlet-node is again positioned at the soil level. In sunlight, young stems change from pale green to reddish. Stems remain viable into early winter, remaining persistent into spring.

Photo 1: As shown, stem is 12 inches long with an additional 7½ inches cut-off at lower right (at white asterisk; black arrows show former attachment of this stem segment). First node bears a 2-leaflet leaf and second node bears a plantlet. A third node (leaf-bearing) and growing stem terminus is at upper left. Photo – April 27.
Photo 2: As this plantlet produced roots, the lower stem continued to grow toward the left. A secondary stem, can be seen on the upper stem (arrow), also growing to the left. The stem to right of plantlet is arched. Photo – April 24.
Photo 3: These several plants were plantlets during the previous spring. Their originating stems, now dead, can be seen. Photo – March 3.

Plants that are several years old develop a stubby, vertical rhizome with an apical crown composed of several growth-points of varying sizes. Each growth-point produces a tight cluster of leaves with larger leaf clusters potentially including a stem and/or flower stalk, just off-center. Upper portion of older rhizomes is covered by bases of current year’s leaves while the lower portion is covered by persistent leaf bases from earlier leaves and remnants of old stems. Two-year-old plants seem to be most productive of stems and flower stalks; plants seeming to deteriorate after their third year. Thick clonal colonies may form. With summertime soil drying and heat, plants often become dormant.

Photo 4: Over winter, plants develop new roots along previous year’s rhizome-growth. Plant at left is approaching its first spring. Plant at right has an inch-long rhizome with 4-inch roots. Newly developing leaves can be seen on right. Photo – February 7.

At mid-spring, a mature plant may have a dozen basal leaves of varying sizes. The reddish overwintering basal leaves are relatively small, flat on the ground and fade as springtime leaves appear. Ascending springtime leaves are considerably larger and with largest leaves being present during flowering and fruiting. Largest leaves may reach 13 inches long (including a 9-inch petiole) with a compound blade that is 4 inches long and 3¾ inches wide. Leaflets are to 3¾ inch long and 2½ inch wide on short petiolules. Springtime leaves have a shiny, medium green upper surface and a dull, pale green lower surface.

Photo 5: Rhizomes are stubby and vertical. Crown of this plant, with two growth points, produced two floral stalks and two stems. Overwintering leaves die as springtime leaves develop. Photo – April 24.

Basal leaves are trifoliate compound. The terminal leaflet and the lateral pair of leaflets, all three of similar size and shape, are obovate to elliptic with wedge-shaped (cuneate) bases and broad rounded apices. Bases of lateral leaflets are oblique. Well-spaced, prominent pinnate secondary veins (set at 30⁰ off midrib) are finely recessed above and expressed below. Secondary veins, evenly spaced and parallel, extend to mucronate tips of prominent triangular teeth along the side margins. The midvein terminates in an apical tooth which is half as wide and smaller than the marginal teeth. Although widely variable, upper and lower blade surfaces generally have spreading to appressed pubescence; that of the lower surface being denser and longer, especially along veins. The slender, long to very long, straight petioles and stubby petiolules are densely pubescent with spreading hairs. Petioles, terete along most of their lengths, have winged bases that serve to position and protect subsequently emerging leaves. The winged bases have pinkish, free-standing, lanceolate apices. These bases are to about 1¼ inches long, of which about ¾ inch is free-standing above the soil.

Photo 6: Female plants are shown. Floral / fruiting stems are positioned below tall basal leaves. Photo – May 16.
Photo 7: Functionally male plants are shown (see Photo 15 for related information). Photo – April 13.
Photo 8: Pubescent petioles of overwintering basal leaves are short as compared to petioles of springtime leaves. The free-standing lanceolate apices of the basal leaves’ winged bases can be seen (pink). This male plant is past bloom stage. Photo – March 22.
Photo 9: This overwintering basal leaf has retained its pubescence. Hairs along petioles are spreading and those of the upper leaf surface are appressed. Photo – February 12.
Photo 10: Pubescence on upper surface of this springtime leaflet is not apparent. Note parallel-pinnate venation, mucronate marginal teeth and smaller tooth terminating midvein. Color is a shiny, medium green. Venation is recessed. Photo – April 16.
Photo 11: Pubescence on lower surface of this springtime leaflet is spreading along the petiolule while that on the blade is appressed. Color is a dull, pale green. Venation is expressed. Photo – April 16.

The April inflorescence develops at same time as when stems begin to grow. The inflorescence, originating just off-center of a current-year leaf cluster, consists of a floral stem bearing to 12+ flowers in a compound umbel. Of a 6-7-inch long inflorescence, about 4¾ inches would be the naked stalk. The stalk is topped by a two-bracted-node from which several small floral leaves and an umbel of 2-4 erect peduncles (to 1½ inches long) emerge. Peduncles, in turn, are topped by a smaller two-bracted-node from which several simple floral leaves and an umbel of 2-5 weak pedicels (to 1½ inches long) emerge. The bracts subtending the peduncle-umbel are obovate while those subtending pedicel-umbel are lanceolate. Additional small lanceolate bracts may occur at the base or along pedicels. The terete stems, peduncles and pedicels are light green and densely pubescent. Floral bracts are slightly pubescent on their exterior and glabrous on their interior. Floral stems of female and male plants have the same structure.

Floral leaves may be compound with 2 leaflets or simple with serrated margins or simple with entire margins. Leaf size and complexity decrease distally. Floral leaves have the same color, texture and pubescence as basal leaves. Smaller floral leaves become entire and lose marginal teeth. When a leaf is serrate, the apical tooth and marginal teeth are the same size. (See a floral stem in Photo 16.)

Photo 12: Floral leaves are mostly simple, becoming smaller and entire (lacking teeth) distally. Of the serrated floral leaflets or leaves, the apical tooth is equal to or larger than the marginal teeth. Color and texture are similar to that of basal leaves. (see Photo 16) Photo – April 21.

Flowers have 5 petals, 20+ stamens (filaments + anthers) and numerous pistils (ovary + style + stigma) covering a domed receptacle. Flowers are male (staminate), female (pistillate) or appear to be perfect (with stamens and pistils) but are functionally staminate. Flowers, ½ – ¾ inch across, have 5 broadly lanceolate sepals interspersed with 5 lanceolate sepal-like bracts united at their bases. In bud, sepals cling to the bud while bracts are ascending. At anthesis, the pale green sepals and bracts form a single layer that is calyx-like. Sepals are positioned between the overlapped petals and bracts. Sepals and bracts are slightly pubescent on both sides. The elongate yellow anthers stand upright on tips of lighter yellow filaments. Styles are tipped with slightly spreading stigmas, both the same color as the filaments. The white petals, which may slightly overlap or be separated, have an obovate upper portion that quickly reduce to a clawed base. The stamens and pistils rise slightly above the petals’ clawed bases with pistils being shorter.

Photo 13: This emerging inflorescence is atop a 4⅞-inch stalk (not shown). Sepals and interspersed floral bracts, united at their bases, can be seen at various stages of flower development. Flower is an inch wide. Photo – April 16.

Photo 14: Receptacles of female flowers are covered with numerous pistils. With weak pedicels, flowers dangle. Photo – April 10.
Photo 15: Flowers from this colony are perfect (with stamens and stigmas). However, the colony has not produced fruits although nearby female plants did (see Photo 17), indicating that flowers of this colony are functionally male. Photo – April 3.
Photo 16: This post-bloom male floral stem bears 2 peduncles (in umbel style), each topped with pedicels (in umbel style). Pedicels bear a single flower. Simple floral leaves and paired bracts can be seen at the base of umbels and along some pedicels. Photo – April 21.

Fertilized pistillate flowers produce fruits (achenes) that are embedded into strawberries maturing in May. Early whitish green strawberries mature to shiny scarlet with the exposed achenes. The ovoid to globoid strawberries are to ½ to ¾ inch long and wide. The calyx of sepals and bracts become appressed to the mature strawberry. Wild Strawberry is said to have a sweeter taste than cultivated strawberries. Year-to-year fruiting success is variable.

Photo 17: Early whitish green strawberries become scarlet with maturity. Fruits (achenes) are embedded. Fruiting success is variable from year-to-year depending on weather conditions. Photo – May 7.
Photo 18: Calyxes are appressed against the strawberries. The tasty strawberries are relished by small mammals (and humans). Squares = ¼ inch. Photo – May 12.

In a sunny to partially sunny garden with well drained mesic soils, Wild Strawberries would add textural variety and provide enjoyment while a person searches for the showy flowers and strawberries. It has active growth from late winter into mid-spring, but small basal leaves remain throughout the winter. Annual flowering can be expected but appearance of strawberries is affected by weather conditions. Being a cool-season plant, it can compete with taller herbaceous plants. A gardener needs to be aware of the plant’s reputation for clonal spreading; however, in a small area, timely removal of stems would restrict clonal spread. Excellent as a ground cover or for erosion control and suitable for naturalizing. Foliage, flowers and fruits are of high ecological value for insects, animals and birds. Fruits (achenes) are dispersed by animals and birds that consume the strawberries.

Wild Strawberry is the only wild species of the genus known in Arkansas. Other “strawberries” which might be encountered are 1) the non-native Indian-Strawberry (Duchesnea indica), whose common name refers to the country of India, and 2) Barren Strawberry (Waldsteinia fragarioides), a plant of conservation concern. Indian-Strawberry can be distinguished by its yellow flowers, having achenes that are not embedded in its scarlet strawberries and floral bracts that are 3-lobed. Barren Strawberry is a ground-cover plant with spreading, shallow, underground rhizomes, very short petioles, yellow flowers and heads of 2-6 dry seeds without an enlarged receptacle.

*Botanically, strawberries, which are not actual berries and not technically the fruit, are referred to as “aggregate accessory fruits”. Examples of true berries are dewberries and blackberries which have achenes immersed in pulp. The fruits of Wild Strawberry are the achenes which are embedded on the outside of the accessory fruit.

**This species has considerable variation in pubescence on petioles, peduncles, pedicels, and stems. Four subspecies/varieties are based on: 1) whether pubescence is ascending, appressed or appressed-ascending and 2) if hairs are visible to the naked eye. Other authorities (including Arkansas) treat these variations as a continuum within the species.

***In 1766, Antoine Nicolas Duchesne documented successful crossing of Wild Strawberry and Chilean/Coastal Strawberry (Fragaria chiloensis) to create the cultivated strawberry (Fragaria × ananassa) with its larger flowers and larger, sweet strawberries.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Old Field Cinquefoil

Old Field Cinquefoil (Potentilla simplex*) of the Rose (Rosaceae) family is a low-growing plant with short rhizomes and 5-petal, bright yellow flowers. The genus name is from the Latin word for “powerful” in reference to medicinal properties of some species of the genus. The specific epithet is Latin for “simple” in reference to the plant’s typically unbranched stems. “Cinquefoil” is French for “five leaves” in reference to the five (sometimes 7) leaflets. In the U.S., it occurs in an area bounded by a line from eastern Oklahoma into Minnesota, across to Maine, thence south along the Atlantic Coast to South Carolina, thence southwest to south Alabama and west to northeast Texas. It also extends into eastern Canada. In Arkansas, occurrence is statewide. It is also known as Five-Finger Cinquefoil and Common Cinquefoil. Habitats include moist to dry sunny sites with various well-drained soils of woodland edges, prairies, rights-of way, disturbed areas and abandoned fields.

Old Field Cinquefoil has palmate basal leaves tightly clustered around a stem. Nodes along stems produce palmate cauline leaves, leafy bracts and flowers. Early in their growth, stems are erect and green, becoming reddish with age. The string-like to cord-like ascending to prostrate stems, to 3+ feet long, have well-spaced nodes. Stems, typically not branched, have node-to-node segments from less than 1 inch to 6+ inches. Stem segments between the lowermost nodes are straight, while stem-segments along mid-stem are broadly arched and the most distal segments are straight. The distal trailing portion of stems is stoloniferous, with stem-tips that root to form clonal plantlets. At the end of their first growth year, new rhizomes are bulbous and smooth with irregular growth rings. Dead stems remain attached to new rhizomes for a year or so.

The shallow, horizontal rhizomes are segmented by growth-years with new growth elongating rhizomes from their distal tips. One to several new growth points may develop along the sides so that the original rhizomes may become branched so that a plant may have several growing tips. With each growing tip bearing several stems, in a favorable habitat, a dense mat of clonal plants may form. Stems bear palmate leaves (cauline leaves) and flowers at their proximal nodes, along with leafy bracts, while more distal nodes bear only leafy bracts. Bracts, to 1 inch long, have one to several lanceolate lobes which may be entire or divided. Diameter of stems and size of leaves and bracts gradually decrease toward the stems’ apices. The cauline leaves have broadened bases similar to those of basal leaves (see below).

Each growth year, a new segment is added to the distal end of rhizomes. This growth pattern results in rhizomes being segmented and roughened by remnants of leaf and stem bases (the first segment being smooth). Each growth year, long fibrous roots grow from the underside of the most recent rhizome segment. When a rhizome reaches its third to fourth year, the older segments begin to decay so that the viable portion of rhizomes is limited to several inches. The tough rhizomes (about ¼ inch in diameter) have a dense, white interior with a pinkish hue.

Photo 1: Active vegetative-growth ends in summer. Basal leaves and roots have been lost while dying stems persist. Plant at right may be 5 years old. Dead stem on rhizome at left grew from the rhizome of the parent plant (not shown). Photo – June 8.
Photo 2: Early basal leaves of the new growth-year appear overwinter. These leaves will die as additional basal leaves appear in spring. Lower left leaf is 1¼ inch wide. Photo – January 13.
Photo 3: From left to right: 1) current year clonal plantlet, 2) second year plant with new bulbous rhizome with irregular growth rings and 3) five-year plant with a branched rhizome (2 inches long) that has a decaying proximal segment. Early basal leaves of #2 and #3 are dying. Photo – March 28.

New basal leaves, appearing overwinter, encircle the growing tips of rhizomes. In spring, as rhizome growth continues, additional basal palmate leaves develop (as earlier leaves die) and long stems appear, also bearing palmate leaves. Basal leaves have 5 (sometimes 7) sessile leaflets while cauline leaves have 5-3 sessile leaflets. Leaflets of cauline leaves tend to be larger and more elongate. Leaflets of basal leaves tend to be obovate (with broadly rounded apices) while those of cauline leaves tend to be more elongate (with broadly tapered apices). All leaflets have wedge-shaped bases. Petioles are initially the same color as lower sides of leaves but become reddish over time. Petioles often have dense appressed pubescence. Bases of petioles, tightly pressed together in a flattened group, have V-shaped “wings” in cross-section (to ⅝ inch long) as a result of having clasped additional emerging leaves and encircled stems. The wings, often hidden in the litter layer, have free-standing, lanceolate apices with straight side-margins.

Photo 4: Close-up photo of plant #3 shown in Photo 3. Fibrous roots grow from most recent rhizome segment. A stem (on left – see arrow) emerges from center of a group of basal leaves – – a folded cauline leaf extends above and behind the stem. Note pubescence of stem. Photo – March 28.
Photo 5: The typical palmate (hand-like) basal leaves have 5 leaflets. Shapes of leaflets vary from obovate to oblanceolate with prominent teeth. These leaves are basal. Photo – March 20.

Basal and cauline palmate leaves are similar. Leaflets, narrowly obovate to broadly lanceolate, have a glossy green upper surface and a pale to silvery green lower surface. Central leaflets are largest, usually 2 or more times as long as wide, and the lower lateral pair is smallest. Leaves may have an “extra” small pair of lateral leaflets (for 7 leaflets) or may have only 3 leaflets. Upper one-half to three-fourths of a leaflet’s margins have 4 to 10 prominent teeth per side. Pinnate venation is finely depressed on the upper surface and finely expressed on the lower surface. Secondary veins terminate at the mucronate tips of the marginal teeth. The midvein terminates leaflets with a smaller tooth. Leaflets are symmetrical across the midvein except lateral leaflets have down-trending midveins. Leaf pubescence is variable in that either surface may be somewhat hairy to glabrous and the petiole, too, has variable pubescence. The pale green petioles, to 6 inches long, become reddish with age. Cauline leaves may be sessile.

Photo 6: Basal leaves at lower right have 7 leaflets. Short, dense pubescence can be seen on upper surface of leaf at lower right. Photo – March 20.
Photo 7: From this lower node of a stem, straight below, the stem continues with a down-arch (toward right foreground). This stem could grow for another 2½ feet. The long-stemmed flower bud (in background) is from the same node. Photo – March 28.
Photo 8: Upper sides (left) and lower sides (right) of leaves are shown. Bases of petioles are V-shaped in cross-section with lanceolate, free standing, basal “wings” at their apices. Blade at upper right is 1½ inch long and 1¼ inch wide.
Photo 9: These cauline leaves are larger than basal leaves (mostly hidden herein) and tend to have more elongate leaflets. Apices of stems are actively growing. Photo – April 17.

The blooming period begins in the early weeks of spring and continues for about a month. The inflorescence consist of a few single flowers per stem on long, very slender pedicels (to 3 inches long). There is one flower per palmate-leaf-bearing node. The lowermost flower is typically at the node with the second lowest cauline leaf.

Photo 10: As can be seen in the upper right corner, the clusters of leaves and leafy bracts grow from the upper side of stems. As shown, stems are still ascending but will become prostrate. Photo – April 27.
Photo 11: As shown, all palmate stem leaves have developed. White arrow points to a node that bears two palmate leaves and a flower bud. Note red stems. Photo – May 1.
Photo 12: Margins of leaflets are prominently toothed with those on the proximal side of lower leaflets extending farther down the leaflet. Secondary veins terminate at the teeth as mucronated tips. Apical tooth is shorter. A leafy bract is shown at lower left. Photo – April 25.

The yellow flowers (to ½ inch wide) have 5 petals, about 20 stamens (filaments + anthers) and 20-50 pistils (ovary + style + stigma); all the same bright yellow. The obovate petals have rounded apices with a shallow apical indention (retuse petals) and a clawed base. Stamens are in a single row encircling a short-elongate receptacle covered with straight, slender and terete styles/stigmas. The styles/stigmas flex from the receptacle in rather random fashion.

Flowers have a calyx of 5 broad-triangular sepals immediately above an epicalyx of 5 triangular-lanceolate floral bracts. Sepals and bracts extend straight-out from the pedicel. Sepals are positioned between the petals and bracts. The dark green, pubescent sepals are broadly triangular with short-acute apices while bracts are broadly lanceolate with acuminate apices. Sepals are shorter than bracts and bracts are about the same length as petals. The elongate anthers, with widened bases, stand upright on tips of filaments. Styles are tipped with tiny, poorly defined stigmas.

Photo 13: Five sepals enclose this bud immediately above five floral bracts. Photo – April 25.
Photo 14: Stamens, in a single row, encircle the head covered with pistils. Apices of petals tend to be retuse. As shown, interior surface of sepals is pubescent. Photo – May 1.

With maturity of fruiting heads, styles/stigmas drop off the receptacle while drying stamens persist as receptacle, sepals, bracts and pedicels remain green. Heads bear an aggregate of one-seeded indehiscent nutlets. The glabrous bean-shaped nutlets, about 1/32-inch long, are tan with a roughened surface. The seeds’ small size and weak attachment suggest that nutlets could be dispersed by strong wind and fallen nutlets could be transported by surface-water flow during heavy rains.

Photo 15: Fruiting heads are an aggregate of indehiscent bean-shaped nutlets. Nutlets have a glabrous, roughened surface. Squares are ¼ inch. Photo – June 21.

Regarding garden use, Old Field Cinquefoil has pleasing visual characteristics (palmate leaves, bright flowers). Flowers provide pollen and nectar for insects and foliage for deer, rabbits and marmots. With its stoloniferous stems, extending as far as 3 feet, it could expand quickly. Should be welcomed in natural areas. May provide a good groundcover to stabilize soil from erosion. Degree of self-seeding is not known.

Three additional species in the genus occur in Arkansas; namely, Dwarf or Five-Finger Cinquefoil** (Potentilla canadensis), Rough Cinquefoil (Potentilla norvegica) and Sulfur or Rough-Fruit Cinquefoil (Potentilla recta). Also, Mock or Indian-Strawberry (Duchesnea indica) is sometimes treated within the genus (as Potentilla indica). Of these species, Dwarf Cinquefoil is most similar. Dwarf Cinquefoil is a smaller plant with smaller and strongly obovate to oblanceolate leaflets, with fewer teeth. Flowers of Dwarf Cinquefoil usually occur from the first stem node and thinner stems are usually prostrate from the start of growth. Dwarf Cinquefoil has been reported from northeastern Arkansas.

*This species has considerable variation in leaf and stem pubescence, to the extent that some authorities have named three varieties. Other authorities (including Arkansas) treat these varieties as a continuum within the species.

**The common name “Five-Finger” is used for both P. simplex and P. canadensis.

Article and photographs by ANPS member Sid Vogelpohl

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New T-Shirts for 2023

We have 5 new T-Shirt designs available on Bonfire. These are made to order and different colors and styles are available for each design. Click on each photo to be taken to Bonfire to place your order.

ANPS receives a small portion of the sale of each shirt – so you’ll be helping support our grants and scholarships program while looking super cool at your next picnic!

Note – these shirts are ONLY available online. They will not be available for in-person purchase at our Spring and Fall meetings.

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2023 ANPS Spring Meeting Information

ANPS Spring 2023 Meeting
May 19-21 in Northwest Arkansas

Everyone is welcome to attend! Meeting registration is only $10 with no pre-registration required. Registration will begin at 5:00 p.m. on Friday, May 19 at the Illinois River Watershed Partnership Watershed Learning Center.

Illinois River Watershed Partnership Watershed Learning Center
221 S. Main St., Cave Springs, AR 72718

Holiday Inn Express and Suites Bentonville
2205 S.E. Walton Boulevard, Bentonville, AR

We have reserved 10 king rooms at a rate of $109.00 plus tax per night and 10 double queen rooms at a rate of $119.00 plus tax per night. Reservations must be received by April 28, 2023 to guarantee these rates. 

Follow the link in the hotel’s name above to book your room, or if you prefer to call to make a reservation be sure to mention that you are with the Arkansas Native Plant Society.

We will have a potluck meal Friday and Saturday evenings. Bring a dish to share or just come and eat! The IRWP Watershed Learning Center has a refrigerator we can use to store food overnight. 

There are also many dining options near the hotel.

The silent auction will begin at 6:00 p.m. on Friday and close at the end of the program on Saturday evening. Proceeds from the auction support the ANPS small grants program, student research grants, and student scholarships! Bring any donations to you would like to include in the auction before 6:00. Auction sheets will be provided. If your item does not sell, you must take it back with you at the end of the meeting.

Several field trips to local areas of top botanical interest are scheduled for Saturday 8:30 a.m. – 5:00 p.m. and Sunday 8:30 a.m. – 12:00 p.m.

You must sign up for field trips on Friday evening to allow for adequate logistical planning. We will also provide directions to each site on Friday evening. 

We advise bringing a hat, sunscreen, water, snacks, and bug spray on field trips!

NOTE: Field trip locations may change due to inclement weather, so check the ANPS website and Facebook for the latest field trip locations in case of rain, as we will post alternative activities there.

EVENING PROGRAMS SCHEDULE – at the IRWP Watershed Learning Center

Friday, May 19
5:00 PMDoors to meeting room open and registration begins; silent auction setup
6:00 PMSilent Auction opens
7:00 PMEvening program begins
7:15 PMBrendan Kosnik, M.S. student in biology at Arkansas State University and 2022 ANPS Delzie Demaree Research Grant recipient, will speak on his research “Discovering the Rare Sedges of Eastern Arkansas”
8:00 PMVirginia McDaniel, Acting Forest Botanist for the Ouachita National Forest, will introduce the informative videos “Glade Restoration on the Ozark-St. Francis and Ouachita National Forests” and “Shortleaf Pine-Bluestem Restoration on the Ouachita National Forest” produced by Fauna Creative with funding from the US Forest Service and The Nature Conservancy
8:15 PMMarson Nance, Director of Land Stewardship and Research, Northwest Arkansas Land Trust, will speak on the topic “Restoration Ecology of Wilson Springs Preserve”
Saturday, May 20
5:30 PMDoors to meeting room open, registration continues
6:00 PMANPS Business Meeting
7:30 PMKeynote Speaker: Dr. Ray Fisher, Research Entomologist at Mississippi State University and adjunct Professor at the University of Arkansas, will speak on the topic “Girdlers, Gallers, and Get-togetherers: tales of plants and arthropods”
8:30 PMSilent Auction closes

Here is a map showing the location of the meeting along with all nearby parking options:

QUESTIONS?  Visit or contact Eric Fuselier at

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Know Your Natives – Hispid Buttercup

Hispid Buttercup (Ranunculus hispidus var. hispidus*) of the Buttercup (Ranunculaceae) family is an upland perennial forb with mostly 3-part basal and stem leaves and has soft spreading (bristly) pubescence on stems and petioles. The genus name is from the Latin for “little frog,” because many buttercups live in moist habitats. The specific epithet is Latin for “with bristly hairs”, in reference to the plant’s pubescence. In the U.S., Hispid Buttercup can be found from Kansas, Oklahoma, Missouri and Arkansas along with a large block of states from Alabama to Wisconsin and eastward to the Atlantic Coast (far-northeastern states excluded). In Arkansas, it occurs across the Interior Highlands (Ozark Plateaus, Arkansas Valley and Ouachita Mountains). Habitats include various well-drained to compacted soils in deciduous woodlands and openings found along ridges, slopes and lowlands as well as in prairies.

Hispid Buttercup is an herbaceous plant with basal leaves at the base of flowering stems. Basal leaves, a darker green than stems, have long petioles with “winged” bases as a result of bases having clasped emerging leaves and stems. Basal leaves vary from early ovate simple leaves to 3-lobed simple rounded leaves to ternately compound leaves with oblanceolate leaflets. While terminal leaflets are symmetrical along their midrib, lateral leaflets are narrower along their distal side. The larger terminal leaflet may or may not be on a short stalk (petiolule) while the opposite lateral leaflets are typically sessile or nearly so. Bases of leaflets may be nearly flat, wedge-shaped (cuneate) or rounded. Side margins of leaves and leaflets are mostly entire while the broad apexes are rounded to coarsely dentate or sharp-pointed coarsely dentate. Leaf blades are to 6+ inches long and 5+ inches wide while petioles may be to 8+ inches long. Petioles and petiolules have long spreading pubescence. Pubescence of upper leaf blades is short, dense to scattered and somewhat appressed while that of the lower surface consists of longer spreading hairs mostly along main veins. Venation is longitudinal. Above petiole-base, petioles are grooved along their upper side and rounded below. Petiolules are terete in cross-section.

Photo 1: In this mid-summer photo, plant is growing new basal leaves which may persist over the winter months. Photo – August 1.
Photo 2: In spring, overwintering basal leaves die with growth of new basal leaves. All leaves shown are strongly 3-lobed and grooved, pubescent petioles can be seen. Photo – March 30.
Photo 3: Basal leaf in foreground is compound with a symmetrical terminal leaflet and a pair of lateral leaflets which are narrower along their distal side. The spreading pubescence of stems can be seen. Photo – April 3.
Photo 4: Venation of basal leaves is longitudinal. Leaves may be highlighted by brown margins and brown-tipped dentate serrations. (An enlarged portion of Photo 3.)
Photo 5: Terminal leaflets (here seen at bottom of photo) of larger basal leaves typically have petiolules while lateral leaflets are sessile. Detached petiole, with spreading hairs, at right. Photo – May 25.

Stem (cauline) leaves occur as widely spaced opposite pairs, near-opposite pairs and singly. Larger leaves tend to be ternately compound with narrowly elliptic to linear leaflets which typically lack lobes or marginal teeth. Distally, leaves become smaller and less complex so that the ultimate leaf may only be a simple, linear leaf. Leaflets of a compound leaf may be disjointed (not meet at a common point) and all three leaflets may have petiolules. Petioles of cauline leaves are significantly shorter than those of basal leaves with lengths decreasing distally. Primary veins are parallel. Shapes of the lowermost cauline leaves may be “transitional” by having characteristics of both basal and cauline leaves – – in regard to leaflet shape, petiole length and lobing.

Stems, few in number, are slender and radiate from the plant center. They are initially erect to ascending until they reach several inches tall. With continuing stem growth, stems become decumbent and may extend a foot from the plant’s center. Stems have one to several widely spaced, leaf-bearing nodes which may produce an axillary side stem or a flower stalk (peduncle). The pale green stems, terete in cross-section and slightly ribbed, typically have dense pubescence of spreading white hairs. Unlike some buttercups, stems in contact with the soil do not develop nodal roots.

Photo 6: Stems, not developing nodal roots, become decumbent as they lengthen. Along with several compound basal leaves, a compound cauline leaf is shown with 3 leaflets on separate petiolules. A fruit-head is shown at upper right. Photo – April 3.

Hispid Buttercup flowers from March into April. The inflorescence consists of terminal, solitary, compound flowers that arise from the uppermost cauline leaf axils. Early flower buds appear near ground level and later flowers are elevated well above basal leaves as stems continue to grow. With continued growth, flowers (and fruits) are seen as being on long slender peduncles. Peduncles (to 1+ inch long) are terete and ribbed. They are the same color as the stem, but usually less pubescent. Flowers can grow to 1 inch across.

Photo 7: Basal leaves become compound with a stalked terminal leaflet and a pair of sessile lateral leaflets. Flower buds, axillary to uppermost cauline leaves, first appear near ground-level. Photo – March 20.
Photo 8: Stems are ascending in their early growth. As shown, pubescence of peduncles is less than that of stems. Cauline leaves consist of 1-3 narrowly elliptic to linear leaflets. Photo – April 7.
Photo 9: Axillary side-stems may develop from lower cauline leaf axils. The axillary flowers are on long stem-like peduncles growing from the uppermost cauline leaf. Partially shown are Sundrops and Ernest’ Spiderwort. Photo – April 3.

The flowers consist of 5 sepals, 5 glossy yellow petals, a ring of numerous stamens (filaments + anthers) and numerous pale-yellow pistils (ovary + style + stigma) sitting on a greenish, conic receptacle. The obovate petals, to ⅝ inch long and to ⅜ inch wide, have bases and longitudinal veins that are somewhat translucent (guides to nectar at petal-base). Yellow filaments, with narrow bases, curve away from the receptacle and ascend as they transition directly into elongate yellow anthers. Anthers are smooth on their exterior and, with pollen release, grooved on their interior. The elongate pistils, evenly spread across the conic receptacle and also curved and ascending, have a skinny ovary tipped with a short style and a pin-point stigma. In bud, sepals are green and boat-shape (with a keel and sharp bow) before becoming yellowish and bowl-shaped when fully developed. The bowl-shape beginning as a flat area surrounding the peduncle. The broad sepals have a pointed apex and a narrow base. Outer surface of sepals has dense, long pubescence. Sepals, about ⅓ inch long, become somewhat reflexed and rather thin as anthesis progresses.

Photo 10: Glossy flowers have 5 petals, a ring of numerous stamens and numerous pistils on a conic receptacle. Coloration at base of petals and veins serve as guides to nectar “pockets” at base of petals (see red arrow). Photo – April 4.
Photo 11: Bowl-shaped sepals are spreading from a flat area surrounding the peduncle. Photo – April 12.
Photo 12: With anthesis, sepals become somewhat reflexed as anthesis progresses. Note obovate petals, long hairs on exterior of sepals and lack of hairs on this particular peduncle. Photo – April 12.

Receptacles have a few to 60 green fruits (achenes). When mature, the asymmetrical, flattened fruits (less than ¼ inch long) consist of a rounded seed, ⅛ inch wide, with an off-set, weakly attached base and a narrow marginal wing, about 1/32 inch wide, extending from fruit base to a sharp apical beak. The narrowly triangular, nearly straight beak (comprised of style and stigma) is firm but not piercing. Wings, too, are firm and well attached to the seed. Seed-area of the glabrous, flattened fruits are slightly thickened above the winged margins. Dry achenes may be dispersed by strong, surface water flow and passing animals.

Photo 13: Stems and peduncles are long. Cauline leaves may have 1-3 elliptic to linear leaflets. Cauline leaf at lower right is transitional between cauline and basal leaves. A basal leaf and its detached petiole are shown at upper right. Photo – May 25.
Photo 14: This cauline leaf has off-set, lanceolate lateral leaflets with parallel veins. Margins of the flattened, rounded seeds are winged with wings joined at seed apex to form a sharp beak. Fruits are asymmetrical. Squares are ¼ inch. Photo – May 27.

Hispid Buttercup, with its fresh leaves and bright yellow flowers in late winter/early spring, is noticeable. It does not seem to be an aggressive spreader and is so unobtrusive that it should be welcome in any garden setting or natural habitat. Plants grow best when in thin mulch or leaf litter. Pollen and nectar attract various bees and flies. Seeds are eaten by game birds and small mammals.

At least eighteen buttercup species or varieties have been identified in the wild in Arkansas (six are non-native). All have glossy yellow flowers except one which has white flowers (White Water Crowfoot [R. aquatillis var. diffusus]). The species most likely to be confused with Hispid Buttercup is Early Buttercup (R. fascicularis). Hispid Buttercup can be distinguished by its 1) lack of tuberous roots, 2) wider leaves and leaflets, 3) later flowers with more ovate petals, 4) spreading sepals and 4) soft, bristly pubescence.

Photo 15: Hairy Buttercup may be confused with Early Buttercup. (shown) Photo – April 2.

*A taxonomic revision placed Swamp Buttercup (R. septentrionalis) into the R. hispidus complex, which has three varieties under this concept: Bristly Buttercup (R. hispidus var. caricetorum) [not known from Arkansas], Hispid Buttercup (R. hispidus var. hispidus) and Swamp Buttercup (R. hispidus var. nitidus). Swamp Buttercup, occurring in Arkansas, has reflexed sepals, achene margins that are twice as wide as those of Hispid Buttercup and long arching-decumbent stems that may develop nodal roots. It typically occurs in riparian or lowland habitats.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Downy Phlox

Downy Phlox (Phlox pilosa*) of the Phlox (Polemoniaceae) family is a semi-evergreen perennial forb with showy flowers of variable color and shape. The genus, Phlox, is derived from the Greek word meaning flame – a reference to flower color of some species. The specific epithet, pilosa, is from Latin meaning “hairy” – a reference to the plant’s pubescence. In the U.S., it occurs in an area bounded from south-central Texas and eastern Oklahoma, north along the eastern boundaries of states from Kansas to North Dakota, then eastward to New Jersey, south along the Atlantic coast to central Florida and then back to Texas; principally excluding the Appalachian Mountains and portions of the lower Mississippi River floodplain. In Arkansas, occurrence is basically statewide. Habitats vary from mostly sunny mesic to dry sandy to rocky sites in open woodlands, prairies and meadows. It is also known as Prairie Phlox.

Plants develop stubby, branched taproots supported by smaller ropy roots and secondary ropy roots which may grow from basal stem-nodes with ground contact. The terete stems, few to many, grow to 18+ inches long. New stems originate overwinter from axillary buds located at nodes at the base of old stems or directly from the root crown. New stems may be erect or ground-hugging and spreading before becoming erect. They tend to be purplish before becoming medium green at flowering. In similar sunny sites, at the time of bloom, plants with few stems have an open structure while those with many stems have a round-mounded structure. The slender stems are stiff, rather tough and densely short-pubescent with hairs that may or may not be gland tipped. The main stem and axillary branches along the upper portions of the stem bear flowers. Late in the growing season, after seed dispersal and dying of flowering stem/branches, short, leafy, secondary branches may develop along the remainder of the stem. These secondary branches tend to survive over winter but die with new spring-time growth.

Photo 1: This mature plant has several gnarled taproots and smaller ropy roots. A stem-remnant from the previous growth-year can be seen (red arrow). New stems may grow directly from the rootstock or from base of old stems (yellow arrows). Photo – August 19.
Photo 2: Basal portion of stems survive through winter. Short leafy branches may develop which survive through the winter, dying with spring-time growth. Photo – January 9.

Leaves occur in opposite pairs – – adjacent pairs rotated 90⁰ (decussate pairs). Initially, nodes of leaf pairs are practically touching along the stem, but nodes become widely spaced with stem growth. Leaves vary from linear to lanceolate and oblanceolate to ovate with rounded to truncate bases and acuminate, sharp apexes. The simple leaves, which grow to 4½ inches long and ¾ inch wide, lack petioles (sessile leaves) and have smooth (entire) margins. New leaves have deeply furrowed midribs above and prominent revolute (curled under) margins while mature leaves become more planar. The initial purplish shading of new leaves becomes medium green above and a pale green below. Other than the midrib, venation is obscure above and below. Leaves are moderately to densely pubescent with short white hairs on upper and lower surfaces. Hairs on the margins of leaves (ciliate hairs) and midrib hairs tend to be longer. Leaf pairs, extending into the inflorescence as floral bracts, become increasingly small. With drying conditions, basal leaves drop off.

Photo 3: Initially, opposite leaf pairs are closely spaced. Leaves and stems are initially purplish, becoming medium green with maturity. Photo – March 3.
Photo 4: New winter-time growth of plants with many stems is ground-hugging. Early growth of branches can be seen at bottom of photo. Photo – March 20.
Photo 5: The simple linear leaves of this non-flowering stem have revolute margins, prominent midveins and obscure secondary veins. Middle leaf on left is 4½ inches long and ½ inch wide. Photo – June 9.

Downy Phlox flowers from April into June. Flowers on the stem and branches are on short, straight, stem-like, pubescent pedicels growing directly from axils of floral bracts. Early in the bloom-period, the inflorescence appears to be of terminal dome-shaped clusters. Clusters, composed of up to 50 flowers, can be up to 3 inches across. As the stem elongates, the panicle-nature of the inflorescence becomes apparent. (See Photo 12.)

The flat-faced flowers grow to ½ inch wide and ¼+ inch long and have five petal-like lobes united at the base into a long slender tube. In bud, lobes are in a tight elongate roll atop the straight tube. The pink to purplish or white flowers typically have a patch of contrasting colors at lobe-bases enhanced by an outline of a lighter color (nectar guides), along with a darkened throat. Nectar guides on white flowers may not be noticeable. Corolla lobes, with unnotched apexes, may be obovate to oblanceolate – lobes of some plants have sharp points. Exterior of flower may be glabrous or the tube may have scattered pubescence.

Photo 6: Lanceolate floral bracts become increasingly smaller toward apexes of stems and branches. Elongate flower buds are tightly rolled. Photo – April 30.
Photo 7: Flowering stems often have several branches; all in bloom at about the same time. Flower shape and color vary. Blue flowers in background are Crested Iris. Photo – April 18.
Photo 8: Apexes of corolla lobes are generally rounded to varying degrees. Corolla lobes of the white-flowered plant here have minutely pointed apexes. Anthers remain within the throat. Photo – April 30.
Photo 9: This many-stemmed plant has white flowers with prominent purplish nectar guides. Photo – April 30.

Flowers, set in pubescent calyxes, have five stamens (filament + anthers) and a three-part fused pistil (ovary + style + stigma) with a nectary disk at the pistil’s base. The white filaments are fused to the tube at varied points so that the yellow, elongate anthers are staggered. Anthers, remaining within the tube, produce yellow pollen. The white style, set atop a smooth pale green ovary, terminates with a three-part spreading stigma positioned well below the anthers. Calyxes, to ½ inch long, have a short cupped tubular base with five very long, lanceolate lobes. Calyx lobes are erect in their lower portion and widely spread in their upper portion. Calyx lobes, which tend to have a purplish tinge, have dense glandular or non-glandular pubescence. Calyx lobes and floral bracts are similar in appearance.

Photo 10: Stem, pedicels, floral bracts and calyx of this plant have dense glandular pubescence. Calyx lobes are erect in their lower portion and spreading in their upper portion. Photo – June 9.
Photo 11: With filaments fused to the tube at varied points, anthers are staggered. Flowers have three-part fused pistils with spreading stigmas. This flower is ¾ inch wide and 9/16 inch long. Pistil is ⅛ inch long.

Following fertilization, ovaries develop into green spherical fruits in late spring. With drying, capsules become light-tan and calyx lobes recurve sharply. The three-chambered, smooth capsules contain several brown to dark brown seeds each with a rounded side and two flat sides. Seed surfaces have irregular bumps (papillae). Seed capsules that drop from plants while intact are buoyant and surface water flow may aid with seed dispersal.

Photo 12: Flowers, on straight pedicels, grow directly from axils of floral bracts. Flowers are arranged in panicles. Bracts and calyx lobes have a similar appearance. Photo – May 27.
Photo 13: Dry calyx lobes recurve sharply to fully expose seed capsules. The spherical, light tan capsules contain several brown to dark brown seeds. Seed surfaces are covered by papillae. Photo – May 27.

In regard to gardening, Downy Phlox can be a specimen plant or share space with other spring-blooming plants in rock gardens, cottage gardens, or prairie settings. Plants grow well in various dry to mesic, well-drained soil in full sun to partial shade. Its early growth and variable flower shape and color and seed capsules add interest. Plants spread by seed but not annoyingly so. It is a great nectar source for moths, butterflies, and hummingbirds as well as a pollen source for small bees.

Photo 14: Downy Phlox with other spring-time plants, including: Wild Geranium, Celandine Poppy and Wild Comfrey. Photo – April 30.
Photo 15: Downy Phlox is a great nectar sources for butterflies and moths, including the showy Eastern Tiger Swallowtails (Papilio glaucus). Photo April 10.

Other species and subspecies of the genus reported in Arkansas are: Broad Leaf Phlox (Phlox amplifolia), Sand Phlox (Phlox bifida subsp. bifida), Starry Sand Phlox (Phlox bifida subsp. stellaris), Wild Blue Phlox (Phlox divaricata subsp. laphamii), Annual Phlox (Phlox drummondii) [native to Texas but considered introduced in Arkansas], Smooth Phlox (Phlox glaberrima), Perennial Phlox / Garden Phlox (Phlox paniculata), and Moss Phlox (Phlox subulata) [introduced in Arkansas but native to portions of the Northeast U.S.]. Of these species, Downy Phlox is most similar to the comparably sized, pubescent Wild Blue Phlox. Downy Phlox can be distinguished by 1) its later bloom period, 2) linear to lanceolate leaves, 3) flowers being variably colored, and 4) lack of clonal sterile stems. Wild Blue Phlox flowers earlier in the spring, has broad leaves, has consistently blue or bluish-purple flowers, has sterile clonal stems, and lacks a tap root.

*Numerous subspecies of Downy Phlox have been described and named by various authorities over the years, and the USDA Plants Database currently recognizes nine based on type, length and location of hairs and leaf shape. In Arkansas, two subspecies are generally recognized: 1) Downy Phlox (Phlox pilosa subsp. pilosa) and 2) Ozark Downy Phlox (Phlox pilosa subsp. ozarkana) based on leaf shape and presence or absence of glandular hairs. Some cryptic other or undescribed subspecies may also occur.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Ebony Spleenwort

Ebony Spleenwort (Asplenium platyneuron) of the Spleenwort Fern (Aspleniaceae) family is a small to medium size, once-cut, evergreen fern. The genus name is from Greek for “without a spleen” which may indicate that plants of this genus were historically thought to treat medical issues relating to the spleen. The specific epithet is from Greek words meaning wide or flattened veins. The common name refers to the dark, lustrous stipe (petiole) and rachis (midrib of blade). Its U.S. distribution is widespread, ranging from eastern Texas and Oklahoma to southeastern Minnesota, across to southern Maine, thence south along the Atlantic Coast and back to Texas. It occurs in additional scattered occurrences in the U.S. as far west as Arizona. Ebony Spleenwort is also found in subtropical and tropical southern Africa (a unique distribution not known for other North American ferns), eastern Canada, and in isolated populations in eastern Europe. In Arkansas, it is reported from all counties. Habitat preferences range from shady to partially sunny sites that may have deep, mesic to wet soils, in fields and open woodlands with a thin litter layer (terrestrial sites) to rock outcrops, rocky slopes and crevices of rocks and masonry walls. Across its broad range, variability of fronds has resulted in classification of a number of forms and varieties, but few such names are recognized today. Ebony Spleenwort hybridizes with several other Asplenium species; those occurring in Arkansas are listed at the end of this article.

Photo 1: Ebony Spleenwort growing in deep sandy soil of a flat woodland with Christmas Fern (upper right) and Blunt-Lobed Cliff Fern (Woodsia obtusa) (lower right). Photo – December 19
Photo 2: Ebony Spleenwort growing in a crevice between boulders in a deciduous woodland. Largest fertile frond is 15 inches long and 1½ inches wide. Photo – October 31.
Photo 3: Ebony Spleenwort growing naturally on the north side of a stacked-rock wall. Photo – November 25.
Photo 4: This tight clump of Ebony Spleenwort plants is on the north side of a woodland margin. Photo – December 6. (see related Photos 6 & 7)

Ferns have a two-phase life cycle: the gametophyte phase (a plant which has one set of chromosomes in each cell) and the sporophyte phase (which has two sets of chromosomes). The sporophyte phase is the most conspicuous. Most of us have probably never seen a fern in its gametophyte phase. During the sporophyte phase, a fern looks like, well, a fern. They bear clusters of sporangia called sori (aka fruit dots) on the underside of the frond or in separate fronds. Each sorus may be protected by an indusium (covering). The sporangia, attached on minute stems, produce the spores. When spores mature, the indusium, if present, shrinks back so that sporangia are exposed; they dry and split, releasing spores to the wind. When a spore lands in a favorable environment, it germinates to begin the gametophyte phase.  This plant, called a prothallus, contains both a structure called an archegonium, which makes an egg, and an antheridium, which makes sperm. Gametophytes are normally found in moist environments because the sperm need to swim to the eggs in the archegonia.  The sperm and egg (which each have one set of chromosomes, just like in humans) join to make the zygote, the first cell of the sporophyte, which actually begins growth directly on, and is briefly nourished by, the gametophyte. For some ferns, the sperm and egg necessary for new sporophyte plants to develop must be from different gametophytes (produced from two different spores). Ebony Spleenwort, however, is capable of self-fertilization whereby viable sporophytes can develop from gametes of a single gametophyte. For information specific to the sporophyte phase of Ebony Spleenwort, see below.

Photo 5: Beyond the indusia, the stemmed sporangia are exposed. Leaflets (pinnae or pinnules) are mostly glabrous with scattered, minute, filiform scales along the rachis and across undersides of leaflets. Photo – Nov 16

Ebony Spleenwort has the ability to reproduce vegetatively by “proliferating buds” that form at the base of fertile and sterile fronds. This is uncommon in ferns. These minute, spherical buds occur in limited numbers. In a favorable environment, while attached to the parent frond, a bud may develop into plantlets with its own rootlets and small fronds. Reportedly, buds that drop-off while lacking rootlets and fronds may still develop into plantlets. These clonal plants remain at the base of the parent plant so that tight clumps of variously aged plants may form. (Herein below, reference to “fertile” and “sterile” fronds relates to the presence or absence of sori, respectively.)

Photo 6: A proliferating bud on this “sterile” frond (white arrow) has developed rootlets and a frond. This bud has a width of 1/32 inch. Length of its frond is ⅜ inch. Red arrows point to a second plantlet that has become detached from the parent plant. Parent fern and plantlets are all from clump shown in Photo 4.
Photo 7: These young plants, probably clonal, came from the tight clump shown in Photo 4.

This non-rhizomatous fern may occur singly, in scattered groups, or clonal colonies (see Photos 1-4). Size of ferns varies considerably depending on moisture, soil depth and sunlight. A terete, mostly vertical, central rootstock elongates year-by-year as new growth emerges from the rootstock’s crown. The rootstock, base rounded, is roughened by the spiky bases of previous years’ fronds. Rootstocks are supported by a dense mass of long, tangled, equal-sized, well-spread, fibrous roots growing from all around the central rootstock.

Photo 8: This plant was in a shady, deep-soil site. It has a stubby central rootstock (⅜ inch wide) with a mass of fibrous roots to 6¾ inch long. Photo – November 9.
Photo 9: This plant was in a crevice between large rocks in a woodland. Central rootstock, shown with mass of rootlets removed, is 2 inches long (as measured between the 2 arrows) and ¼ inch wide. Photo – December 28.

Fertile and sterile fronds are different in size, shape and leaflet shape, thus a dimorphic fern. New fertile fronds emerge in spring as curled-up fiddleheads while the previous year’s sterile fronds remain viable. New sterile fronds emerge in early summer. Erect fertile fronds are to 16 inches long (plus a 2-inch stipe) and 2 inches wide. The smaller, low-arching to prostrate sterile fronds are to 6 inches long (plus a ½-inch stipe) and 1 inch wide. Both fertile and sterile fronds have a narrowing base and apex. Fertile fronds may have an overall equal width except for the apex (oblong-lanceolate) or be widened at mid- or upper-frond (elliptic to oblanceolate). Sterile fronds may be linear to oblanceolate and may be laterally curved. Initially green, the stipe and rachis quickly become a lustrous dark purplish to reddish brown. With winter temperatures, the brittle fertile fronds tend to become broken and mostly die off while the later growing, ground-hugging sterile fronds remain green into spring.

Photo 10: These fertile-frond fiddleheads are poised for springtime emergence. Length of central rootstock is ⅜ inch. Same plant shown in Photo 8.
Photo 11: This springtime plant has three new fertile fronds with apexes still in fiddleheads. Several erect to reclined, old fertile fronds remain along with several low-arching to prostrate old sterile fronds. Photo – April 18.

Fertile fonds may have up to 50 pairs of alternate leaflets while the shorter sterile fronds may have up to 30 pairs. Initially triangular, most leaflets of fertile fronds become oblong to linear-oblong with leaflets near the base remaining smaller and retaining a triangular shape. Leaflets of fertile fronds may be to about 1 inch long and ⅜ inch wide. Leaflets of sterile fronds are to about ¼ inch long and 3/16 inch wide.

The evenly spaced medium to dark green leaflets have stubby, green petiolules (stalks of leaflets) and straight midribs set perpendicular to the terete rachis. Leaflets of fertile and sterile fronds have an ear-like extension (auricle) on the distal side of leaflet base. Leaflets of sterile fronds are more rounded and more closely spaced than those of fertile fronds so that rachises of sterile fronds are mostly hidden, when viewed from above. At the apex, leaflets decrease in size and merge to form an acute to obtuse apex. Rachises are mostly glabrous except for a few scattered, small to minute filiform scales along the stipe and rachis, increasing somewhat toward the stipes’ bases, and continuing onto the undersides of leaflets. Pinnate veins are obscure on the upper leaflet surface and, on the lower surface, the flattened secondary veins are only slightly visible. Secondary veins, without noticeable branching, are free (they do not reach leaflet margins).

On the lower sides of fertile frond leaflets are a double row of straight, elongate-oblong sori (the clusters of sporangia), to 1/16 inch long. Sori are positioned obliquely to either side of the central vein. Sori, aligned with the secondary-vein pattern, are positioned between the leaflet’s central vein and the low-points of the serrate to dentate margins. The number of sori on any particular leaflet varies from few to about 15 alternate-pairs. Sori are initially covered by a translucent to silvery indusium attached to the leaflet along one side – the side away from the central vein. Within each sorus, minute, spherical sporangia are atop minute stalks. In late summer into fall, indusia split to expose these tannish sporangia so that, upon drying, the dust-like spores can be released and dispersed by wind. With spores having been released, the sporangia have a frazzled appearance.

Photo 12: Ferns are dimorphic. A 15½-inch-long fertile frond on left (in 2 sections) is displayed to show upper and lower surfaces. Sterile fronds on right are displayed to show upper surface. Photo – December 19.
Photo 13: Display shows lower sides of sterile fronds. Along with sterile fronds being smaller, prostrate, and sometimes laterally curved, leaflets are more round and more closely spaced. Frond at lower left is 2 inches long. Photo – December 6.
Photo 14: Sori are positioned diagonally between the central vein and the low-points of the serrate to dentate leaflet margins. Sori are protected by translucent covers, called indusia (see arrow). Photo – November 16.
Photo 15: A pair of fertile fronds – lower side shown on left and upper side on right. Auricles are on the distal margin of leaflets; arrows indicate direction of frond apex. Photo – November 9.
Photo 16: With spores dispersed, sporangia have a frazzled appearance. Photo – December 15.

Ebony Spleenwort hybridizes naturally with several other species of the genus – some recorded in Arkansas. A sterile hybrid with Walking Fern (A. rhizophyllum) is Scott’s Spleenwort (A. x ebenoides). A sterile hybrid with Lobed Spleenwort (A. pinnatifidum) is Kentucky Spleenwort (A. x kentuckiense). Both hybrids are of conservation concern. Hybridization between Ebony Spleenwort and Mountain Spleenwort (A. montanum), along with a back-cross, has resulted in a fertile species – Bradley’s Spleenwort (A. bradleyi).

This small to medium sized, evergreen fern has delicate fronds which add fine-detail to a garden setting. It contrasts nicely with broad-leaf plants as well as with other ferns. This non-aggressive fern is suitable for fern gardens, rock gardens, and natural areas in sandy to loamy soils as well as rocky areas. Partial sun to dappled shade is acceptable where soils are typically moist and drainage is good. It may occur naturally in stacked-rock and masonry walls.

As many as nine additional species and four hybrids of Asplenium have been reported to occur in Arkansas.* These other species and hybrids are mostly limited to rocky outcrops; whereas Ebony Spleenwort is also found in terrestrial habitats. Additionally, characteristics that separate Ebony Spleenwort from the other Arkansas spleenworts include: 1) More obvious dimorphic fronds, 2) Alternate leaflets with basal auricles, 3) Leaflets of sterile fronds rather oval-shaped and closely spaced and 4) Dark purplish to reddish brown stipe/rachis throughout. It is most similar to Black Stem Spleenwort (aka Little Ebony Spleenwort) (Aspelnium resiliens). However, both the fertile and sterile fronds of the smaller Black Stem Spleenwort are erect and about the same size and shape, and its leaflets are opposite.

*Spleenwort species and hybrids reported to occur in Arkansas:

Bradley’s Spleenwort – Asplenium bradleyi
Scott’s / Dragon Tail Spleenwort – Asplenium x ebenoides
Graves’ Spleenwort – Asplenium x gravesii
Kentucky Spleenwort – Asplenium x kentuckiense
Mountain Spleenwort – Asplenium montanum
Lobed Spleenwort – Asplenium pinnatifidum
Ebony Spleenwort – Asplenium platyneuron
Black Stem / Little Ebony Spleenwort – Asplenium resiliens
Walking Fern – Asplenium rhizophyllum
Wall-rue – Asplenium ruta-muraria
Northern / Forked Spleenwort – Asplenium septentrionale
Maidenhair Spleenwort – Asplenium trichomanes
Trudell’s Spleenwort – Asplenium x trudellii

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Rough Leaf Dogwood

Rough Leaf Dogwood (Cornus drummondii) of the Dogwood (Cornaceae) family is a small, deciduous tree with opposite leaves, open clusters of small white flowers, and striking, decorative white fruit. The genus name derives from the Latin for “horn” in apparent reference to the hardness of the wood. The specific epithet recognizes Scottish botanist Thomas Drummond (1790-1835) who collected plant specimens from the western and southern U.S. The species occurs from eastern Texas to southeast South Dakota, east to Alabama and Ohio. In Arkansas, occurrence is mostly statewide with a notable gap in the counties of the Gulf Coastal Plain––perhaps explained by undercollecting. Habitats include various dry to wet soils on sunny and shaded sites, such as woodlands, woodland openings and borders, stream banks, fence rows and abandoned fields. Rough Leaf Dogwood is abundant along the Arkansas River.

Trees grow to 15-20+ feet tall from shallow, spreading roots that sucker to produce clonal trees. Spacing of trees in a colony may be tight or open, as determined by the age of the colony, shading, and rockiness of soil. Trees on more sunny sites develop a dense, broad, leafy crown, while crowded or shaded trees become tall with only a few erect branches. Some branches may exhibit a fast rate of growth (1+ feet per year) reaching for light. Epicormic branches may sprout directly from the trunk.

Photo 1: Trees on sunny sites have dense leafy twigs. To maintain a single trunk, suckers of this tree are removed. Yellow flowers at lower right are those of Yellow Crownbeard.

New twigs, initially pale green with dense, short pubescence, become reddish on their sunny side over several years before becoming gray and glabrous with small white lenticels that roughen with age. Twigs are straight. As they mature, the thin bark becomes shallowly fissured, splitting into small rectangular plates aligned along the branch. Fissuring becomes more pronounced on expanding trunks, with plates remaining relatively small and fairly tight. Lenticels eventually become lost on the rough texture of the bark.

Photo 2: Trunks of a colony are of various ages and sizes. New suckers may add trees beyond the perimeter of a colony or within a colony. These fissured trunks have characteristic small rectangular plates aligned with the trunk.

Overwintering, short, slender twigs (1-2 inches long) have small, valvate (2 scales in a praying-hand position) buds. With spring, twigs develop a terminal pair of opposite leaves and one to several pairs of lateral leaves. Most new-twig growth, both vegetative and reproductive, originates from terminal buds. Lateral buds often remain dormant or produce short-lived, stubby twigs. A reproductive twig’s terminal leaves subtend a floral cluster, as well as axillary buds. Vegetative twigs’ terminal pair of leaves subtend a single terminal bud. On sunnier sites, tips of robust twigs become congested with branches and inflorescence peduncles, making this architecture rather obscure.

Photo 3: Pairs of opposite twigs grow from the tips of the previous year’s fertile twigs, forming a Y-shape. Fertile and vegetative twigs become reddish on their sunny side over several years before becoming gray. Photo – November 19.
Photo 4: As paired twigs develop into branches, the branch on the upper side tends to become dominant. With the aging of branches, lenticels become less noticeable. Lowest branches in this photo are 6 feet above ground. (See lenticels in Photo 15.)
Photo 5: These trees, on a steep rocky slope, are in the understory. When falling oaks bent some trees, adventitious buds sprouted along the trunks and developed into erect stems.

The opposite, simple, ovate to elliptic leaves are about 4-6 inches long (including a 1-inch petiole) and 2-3 inches wide, with wedge-shaped (cuneate) to rounded or oblique bases and acuminate to abruptly acuminate tips. Leaves are green above and lighter below, with the sunny side of petioles becoming reddish. Pinnate venation is recessed above and expressed below, the secondary veins arching toward, but not reaching, the leaf apex. Both surfaces are pubescent, with moderately scabrous hairs above and softer hairs beneath––the upper surface feels slightly rough. Twigs and petioles are also hairy. In fall, leaves become orangish to purplish with distal leaves somewhat persistent.

Photo 6: Sunny sides of the pubescent twigs and petioles become reddish. A single terminal axillary bud occurs on the vegetative twig (left) and a pair occurs on the fertile twig (right) after the inflorescence has been shed. Bud scales are valvate. Photo – September 20.
Photo 7: Bases of the ovate to elliptic leaves may be oblique and apexes may be acuminate to abruptly acuminate. Veins are prominent on upper and lower surfaces. Well-spaced secondary veins are arcuate. Photo – September 29.
Photo 8: Dense, softly scabrous pubescence of upper surface (left) feels slightly rough, while villous hairs on lower side (right) feel soft. Hairs are not tightly appressed (as compared to Gray Dogwood – see below). Photo – November 5.

The inflorescence, from May to June, to 4 inches wide and 2 inches long, comprises a broad, rather flat-topped panicle on one or a few floral stalks. Fifty to eighty small white to creamy white flowers terminate the twigs of the current year. The pubescent branching stalks and pedicels redden as the fruits mature to white.

Photo 9: Long-stalked flower clusters are terminal on current year’s twigs. At upper left, with vigorous growth, short infertile secondary twigs may grow from the base of the inflorescence. Photo – May 10.

Flowers, about ¼ inch wide, have 4 sepals, 4 petals, 4 stamens (filament + anthers), and one pistil (ovary + style + stigma). Sepals, petals (about 3/16 inch long), and stamens (also about 3/16 inch long) are attached at the summit of the inferior ovary. The oblong anthers, set see-saw fashion at the narrowing tip of the filaments, are elevated higher than petals and stigma. The flattened stigma is at the apex of the erect style. A prominent nectary encircles the base of the style.

Photo 10: The firm oblong-lanceolate petals are wide-spreading to the point of being down-flexed. Straight filaments position anthers above the post-like style. Photo – May 15.
Photo 11: Flower clusters, terminal on current year twigs, are flat-topped to slightly domed. Anthers, stigma and nectary ring are a slightly darker color than petals. Stamens drop as flowers begin to fade.
Photo 12: All flowers of panicles bloom and fade at the same rate. Panicles are wider than long. Leaves are loosely folded along their midribs. Photo – May 25.

In August and September, the immature green drupes become white and fleshy as the floral stalks, floral branches, and pedicels become reddish. Each drupe, a slightly flattened sphere about ¼ inch across, contains a single, smooth stone. A dark, rimmed depression with persistent sepals at the fruit’s apex marks the former attachment point of the petals and stamens.

Photo 13: Fruits have a central apical scar that persists from the base of the petals and stamens. Stalks and branches of the inflorescence become red as fruits mature. Photo – July 29.
Photo 14: Mature white, flattened-spherical fruits contrast with the reddish floral branches and green leaves. Tiny persistent sepals can be seen on the rim of the scar. Photo – August 22.
Photo 15: Fruits are a favorite of many song birds as well as ground-dwelling birds. Light colored lenticels can be seen on the twig extending to right. Photo – September 14.
Photo 16: If fruits are not taken by birds, stalks dry and fruits shrivel. Fruits contain a single spherical stone. Minute sepals persist on some fruits (see red arrow). Photo – October 17.

In regard to gardens, Rough Leaf Dogwood has a strong suckering tendency and, for a single-trunk tree, would need continual sucker control. It will grow in the understory, but, depending on degree of shading, its structure may be sparse and flowering and fruiting may be limited. This small tree is ideal for a larger naturalized area, for property barriers, and bank stabilization. Its leafy growth, flower clusters, fruits and fall foliage can be showy. Fruits are highly prized by a wide variety of birds and mammals.

Photo 17: Fall foliage can be colorful with leaves at the ends of twigs persisting for up to a month. White arrow (lower left) points to the apex of a fertile twig where the infructescence has dropped off and a pair of axillary buds are present. Photo – November 8.

Five other dogwoods occur in Arkansas: 1) Alternate Leaf Dogwood (Cornus alternifolia) with alternate or whorled leaves and twigs as well as panicles of small white flowers and blue fruits, 2) Flowering Dogwood (Cornus florida) with showy white bracts surrounding a densely clustered flower head and red fruits, 3) Stiff Dogwood (Cornus foemina) with panicles of small white flowers and blue fruits, 4) Silky Dogwood (Cornus obliqua) with panicles of small white flowers and blue fruits, and 5) Gray Dogwood (Cornus racemosa) with panicles of small white flowers and white fruits. Of these, Rough Leaf Dogwood is most likely to be confused with Gray Dogwood which has a similar growth habit and inflorescence. However, Gray Dogwood is more shrub-like, has panicles that are about as tall as wide, and its leaves are less pubescent, with smooth upper adaxial surfaces and abaxial hairs being appressed.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Downy Lobelia

Downy Lobelia (Lobelia puberula) of the Bellflower (Campanulaceae) family is a pubescent, herbaceous perennial bearing showy racemes of blue to lavender flowers. The genus name recognizes Matthias de l’Obel, a Flemish 16th-century physician and botanist who is credited with being the first to attempt to classify plants by attributes other than their medicinal uses. The specific epithet is the diminutive of the Latin puber, downy. In the U.S., Downy Lobelia occurs in a northeast-trending swath from eastern Texas and Oklahoma to the Atlantic Coast. In Arkansas, the species occurs across most of the state except for the northernmost counties and eastern portion of the Mississippi Alluvial Plain. Habitats vary from sunny to partially shaded bottomlands and mesic uplands: deciduous and pine woodlands, forest borders, meadows, ditches, and rights-of-way.

In early spring, an erect stem grows from the fibrous-rooted crown, the diameter of the root crown only slightly larger than that of the stem. Stems are slender, pale green to reddish, to ⅛ inch at base, growing to 3 feet tall. They are unbranched (unless their tips are damaged) and covered with dense, short, soft pubescence. Dry, naked stems may persist into the next growth-year.

Photo 1: A new stem grows from the crown of the stubby, erect, elongated main root. Photo – July 14
Photo 2: When damaged, several axillary stems may develop below the damage. Stems are densely pubescent. Photo – September 19.

Alternate simple stem leaves decrease in size upwards into the racemose inflorescence where they become floral bracts. Leaf shape varies: from ovate to elliptic and oblanceolate below the raceme, triangular to short-lanceolate within the raceme. Leaves are narrowed to short-petiolate, sessile or even clasping bases. Leaf margins vary from entire to finely and even coarsely serrate with sharp (mucronate) tips. Tips of leaves and bracts may bear white calluses due to transpiration of the plant’s white sap. Dense pubescence of leaf surfaces is similar to that of stems. Pinnate venation is obscure on the upper surface, but well expressed on the lower surface. Midribs of both surfaces are raised. Largest leaves may be 4+ inches long and 1½+ inches wide.

Photo 3: Dense pubescence covers the stem and upper and lower leaf surfaces. The crinkled leaf margins are not ciliate, but become highlighted in red in more sunny settings. Leaf-size diminishes upwards.
Photo 4: These sessile leaves, from a single stem, vary from ovate to broadly triangular to lanceolate and bear entire to slightly serrate margins. Upper surface displayed on left, lower surface right. Pinnate veins are obscure on upper surface. Photo – September 19.
Photo 5: These sessile leaves, from a single stem, are oblanceolate to deltoid with margins that have fine to coarse serrations. Upper surface displayed on left, lower surface right. Lower-left leaf is 2 inches long. Photo – October 17.

Blooming from late August into October, the inflorescence, along the upper third to half of the stems, is a raceme. Flowers in bloom are congested near the tip of the raceme but become spread out in fruit as the rachis elongates. Flowers are secund––aligned on the sunny side of the stems––and disposed spreading to ascending from the rachis on short, ascending pedicels, ⅛-¼ inch long. They are subtended by single bracts that decrease in size distally.

Photo 6: Developing flowers are amply spaced; flowers in bloom are congested near the tip of the inflorescence. Appearing to be sessile, flowers have short pedicels that hug the rachis.

Corolla morphology is complex and best understood from pictures rather than description. Suffice it to say that the showy, blue to lavender, tubular corollas are bilabiate, or 2-lipped. The upper lip is narrowly and deeply split into 2 lobes, the lower lip prominently 3-lobed, forming a landing pad for pollinating insects. Exterior of the entire corolla is uniformly pubescent, the interior glabrous.

Photo 7: Flowers are secund along the rachis. Central lobe of lower lip may be variably white. Note change of leaf size and shape along stem (below) and rachis (above). Photo – September 25.
Photo 8: The tubular flowers are 2-lipped. The upper lip is split, comprising 2 lanceolate lobes; the lower lip divides distally into 3 broad, spreading lobes.

Flowers, to about ¾ inch long, have 5 white to lavender stamens (filament + anther) that are disposed around the style and stigma––the ovary is inferior. The slightly pubescent filaments, standing free along most of their length, become fused near their tips where they bear elongate, pubescent, gray anthers that are also fused, into a ring. At early-anthesis, the style is surrounded by the filaments with the stigma enveloped by the anther ring. After pollen is shed, style growth protrudes the rounded stigmas beyond the ring, where the pollen is available to forgaging insects. The anther ring remains in the throat of the corolla.

Corollas are surrounded by a short calyx tube and 5 prominent, linear-lanceolate lobes. Calyx is medium green to reddish in sunny areas, with ciliate lobe margins. The inferior ovary is densely pubescent.

Photo 9: The knobby stigma becomes exserted while the anther ring remains within the throat (see flower at upper right-center). Note ciliate calyx lobes.
Photo 10: Calyx lobes are linear-lanceolate from a broad base. Lobe margins, with ciliate pubescence, are typically entire but may be serrated. (Photo taken down-rachis.)
Photo 11: Display shows 1) pale green receptacle with reddish calyx lobes, 2) pale green style with knobby stigma, 3) two lanceolate lobes of the upper lip, 4) lower lip with three broad lobes, and 5) filaments joined distally and topped with the anther ring.

After flowers fade, the shriveled brown corolla, stamens and style/stigmas remain attached at the summit of the ovary. The inferior ovary below the calyx enlarges into a conic capsule at maturity. Tightly packed ovules develop into minute, yellow-brown seeds. When the glabrous capsules dry, the tips of the 2 valves dehisce separately so that a pair of gaping pores appears, side-by-side. Dry capsules quickly disintegrate. Each capsule may produce hundreds of seeds. Surface of seeds is tuberculate. Seed dispersal is by wind and surface water.

Photo 12: Drying flower parts remain attached to developing capsules. The leathery calyx lobes hide and protect the capsule. These floral bracts have coarse serrations. Photo – October 17.
Photo 13: With calyx lobes and dry flower parts removed, the exterior of the developing capsules can be seen. The short pedicels (¼ inch long), hugging the rachis, have several appressed, tiny, linear bracteoles.
Photo 14: The conic capsules have axile placentas attached to a partition separating the 2 valves. This capsule is ¼ inch long and 3/16 inch wide. Ovoid seeds are tuberculate (see uppermost seed on left).
Photo 15: The apex (as shown) of this dry capsule (3/16 inch wide), having dehisced, has 2 gaping pores separated by the partition (see arrows). Seeds shown in inset photo are about a third of the seeds in this particular capsule. Squares = ¼ inch. Main Photo – October 14. Inset Photo – October 30

An additional 5 species of Lobelia occur in Arkansas: Pale Lobelia (L. appendiculata), Cardinal Flower (L. cardinalis), Indian Tobacco (L. inflata), Great Blue Lobelia (L. siphilitica), and Pale Spike Lobelia (L. spicata). Downy Lobelia is distinguished by its dense pubescence on stems, leaves/bracts, rachis, and exterior of corollas. Unlike the somewhat similar Great Blue Lobelia, flowers of the smaller Downy Lobelia are more loosely spaced and oriented to the sunny side of the raceme.

Downy Lobelia, although not especially eye-catching, should be welcomed in a natural area or practically any garden with mesic to wet soil and partial to full sun. It is a small, erect, non-aggressive herbaceous plant which can be attractive throughout the growing season. Plants in wet, sunny habitats are stouter with more flowers and healthier fruits. Great nectar sources for swallowtails and hummingbirds. May be grazed by deer.

Article and photographs by ANPS member Sid Vogelpohl

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Know Your Natives – Butterfly Weed

Butterfly Weed (Asclepias tuberosa) of the Dogbane (Apocynaceae) family has clear sap (not milky) and showy orange (reddish orange to uncommonly yellow) flowers. The genus name honors the Greek god of medicine, Asklepios. The specific epithet is Latin for “swollen,” a reference to the roots. The species is widespread and common from eastern Texas to Minnesota, east to the Gulf and Atlantic coasts. Disjunct populations occur in the Four-Corner States. In Arkansas, plants grow statewide. Other common names include Butterfly Milkweed, Orange Milkweed, and Pleurisy Root (historically used to treat pleurisy). Preferred habitats are open areas with dry to mesic, well-drained soils: rocky uplands and slopes, open woodlands, prairies, fields, and rights-of-way.

Photo 1: Butterfly Weed has clear sap and nectar that attracts swallowtails and other butterflies. This is the summer form of Zebra Swallowtail (Eurytides marcellus).

Butterfly Weed typically occurs as an erect, perennial herb, 1-2½ feet tall, from a large, tough, knobby crown. Descending taproots may be 1-1½ feet long. Around the first of April, one or more densely pubescent stems sprout directly from the rootstock. With sufficient, late-season soil moisture, spring-like shoots sprout from both the rootstock and mature stems. Plants survive droughts well, but as soils dry out, stems may straggle or die to the rootstock. At the end of the growth year, stems quickly disintegrate.

Photo 2: These mid-April stems, with prominent pubescence, are most likely from a single rootstock. Old stems, as seen, disintegrate over winter.
Photo 3: The erect, pale green spring-time stems are not branched. In early May, most stems of this plant terminate with developing inflorescences.
Photo 4: After a dry period, this plant (may be two plants) ceased growth; some stems died and surviving stems became scraggly (one bearing seed pods). With improved soil moisture, new stems sprouted from the rootstock, but died again with further drying of soil.

Leaves are alternate, oblong-lanceolate to lanceolate, sessile or short-petiolate, 3½ inches long and 1 inch wide. At first crowded together, leaves become well-spaced as stems elongate, gradually decreasing in size upwards. Leaf pubescence is dense on both surfaces, that of the lower surface longer, especially on the midvein––the lower surface feels fuzzy. Margins are narrowly revolute.

Photo 5: Alternate leaves are oblong-lanceolate to lanceolate with narrowly revolute margins. Caterpillar is Unexpected Tiger Moth (Cycnia inopinatus).
Photo 6: Leaves have pubescent surfaces––the lower surface more so. The sessile to short-petiolate leaves have rounded, truncate, or cordate bases. Venation is weakly pinnate. Lower leaf of inset is 1⅞ inches long and ½ inch wide.

Plants produce terminal clusters of flowers in spring and, often, again in summer after rainfall. Clusters consist of multiple umbels that are from 1-2½ inches wide with 8-25 closely spaced flowers per umbel. A loose calyx with 5 light green lobes encloses the flower bud. As buds enlarge, the green color transitions to orange. Within a flower cluster (2-6 inches across), together with a central umbel, several diverging, spreading, floral branches bear a few to a half-dozen additional umbels, in straight-line sequence. Central umbels and innermost umbels on floral branches bloom first, with all flowers of an umbel blooming at the same time.

Photo 7: In uppermost flower cluster, flower bud development of the central umbel (topmost) is more advanced than that of the umbels immediately below––the emerging corollas have grown beyond the tips of the calyx lobes. Monarch caterpillars prefer to forage on the freshest growth.
Photo 8: This terminal inflorescence has a central umbel and two floral branches with the umbels on the branches in a straight-line sequence. All flowers of an umbel bloom at the same time.

Umbels are rounded in outline (as seen from above) and nearly flat (as seen from the side). Peduncles (½–2½ inches long) grow directly from floral branches, often opposite a leaf. Pedicels are about 1 inch long. Peduncles, pedicels and calyx lobes are pubescent, with hairs of peduncles longer and those of the calyx lobes on the exterior only.

Photo 9: The sturdy, pubescent peduncles grow directly from the stem, often opposite a leaf. Straight, slender, less hairy pedicels, attach at the tip of the peduncle to form the umbels.
Photo 10: This dense inflorescence combines that of several, closely spaced stems. Umbel at upper center has begun to fade. Leaves darken with age.

Flowers in bloom consist of a calyx with 5 strongly reflexed lobes hidden by a corolla with 5 strongly reflexed lobes––a perianth typical of many angiosperm flowers. The distinctive structure of the complex milkweed flower is the corona or crown, here comprising 5 erect hoods, each with an exserted, curved horn. An additional morphological anomaly of the milkweed flower is a central column or anther head formed by the fusion of the 5 anthers to the style tip. The petal-like hoods (to ¼ inch long) extend from the base of a tube formed by the fusion of the staminal filaments. The hoods hold the nectar attractive to pollinating insects, in this species, mostly butterflies and bumblebees. A longitudinal section of a flower reveals yet a third unusual structure: the pistil is compound, comprising two carpels, however, they are fused together only above the ovaries to form a single style. Each ovary is separate from its partner.

The adaptive significance of these floral novelties is fascinating. Pollen grains are not granular but cemented together into packets called pollinia––a departure from the norm found only in the milkweed subfamily of the dogbanes and in the unrelated orchid family. There are two pollinia in each anther. As the flower matures, pollinia of adjacent anther-halves become connected by threadlike translator arms to a small secretion of the anther head called a corpusculum or gland. A corpusculum is positioned directly above each of 5 slits––vertical openings that form between the 5 adjacent anthers. When a pollinating insect collects nectar, a leg may inadvertently enter a slit and become snagged by the notched base of the corpusculum. As the insect flies away with an attached corpusculum, the adjacent pair of translator arms with their pollinia is pulled out. The unique contraption––one corpusculum, 2 translator arms, and 2 pollinia––is called a translator. As the insect feeds on other flowers, the translator arms dry and rotate the pollinia, orienting them for a perfect fit into the stigmatic slit of another flower. If a pollinium is then accidentally inserted into a slit, the pollen grains within the pollinium germinate, produce pollen tubes that grow down the style into the ovary, and fertilization of more than 100 eggs is consummated. The stigmatic slits provide both a site where insects can most easily snag a corpusculum as well as an opening into the stigmatic surface of the style, where the pollinium can effect pollination.

Photo 11: Petal-like hoods, forming the corona, are appendages of the staminal filaments, and the exserted horns are appendages of the hoods. Tiny black spots (one at white arrow) between the hoods are the corpusculums that sit above the stigmatic slits.
Photo 12: With corolla and crown hoods removed (#1 and #6, respectively), the following structures can be seen: the anthers (#3) and anther wings (#2) that form the stigmatic slits, stigma head (#4), and stigmatic slit with corpusculum (#5) directly above it.

Typically, only one flower of an umbel develops fruit and only one of the two ovaries of a fertilized flower matures. Fruits are spindle-shaped, single-suture pods (follicles) that stand erect on descending stalks (pedicels). They are smoothly short-pubescent, to 6 inches long and 3/4 inch wide, with seeds along a placenta attached at the suture. When mature and dry, the light tan, papery pods split along the suture from tip to base so that the placenta becomes free-standing. The ⅛-inch, flat, ovate, brown seeds are stacked in the lower part of the pod with long silky, white, apical hairs (1½ inches long) extending toward the narrowing pod tip. As pods gradually open wide on sunny days, breezes tug out the hairs with attached seeds for short- to long-distance dispersal. (Dispersed seeds may not be viable due to predation of ovules by milkweed bugs or dry soil conditions.)

Photo 13: Pods are double-walled when green and feel spongy. Stalks of the pubescent pods are twisted below the somewhat persistent calyx. This pod is 3¼ inches long.
Photo 14: In early October, these Monarch caterpillars eat the freshest leaves. The erect pods are thickened along their lower portion where developing seeds are located.
Photo 15: Large Milkweed Bugs (Oncopeltus fasciatus), both nymphs and adults, feed destructively on developing seeds by inserting their proboscis through the pod wall (see adult on right).
Photo 16: Dry follicles split along their one suture so that the placenta becomes free-standing (see upper pod). Pod on left did not develop fully.

The showy Butterfly Milkweed is a “must have” for well-drained soils of natural areas and most gardens, especially if soil moisture is consistent. The hardy species has outstanding aesthetic appeal with its erect stems and prominent flowers and pods. A nectar source for hummingbirds, swallowtails, fritillaries and the Monarch. Although the sap is considered toxic, the plant hosts caterpillars of the Monarch (Danaus plexippus) and the Unexpected Tiger Moth (Cycnia inopinatus). Ovules within green pods are consumed, from the outside, by adults and nymphs of the Large Milkweed Bugs (Oncopeltus fasciatus) and Small Milkweed Bugs (Lygaeus kalmii). Aphid infestations can stop fresh growth. With drying soils and summer heat, stems become ragged or die back to the ground, but renewed fresh growth may occur with improved moisture. Dry, empty pods can last for years in dry arrangements.

Photo 17: In early June, these Butterfly Weeds blend with other native species in a garden setting including Dittany (Cunila origanoides), Hairy Blazing Star (Liatris hirsuta) and Rattleweed (Astragalus canadensis).

Butterfly Weed, one of 14 species of Asclepias that occur in Arkansas, is readily distinguished by its orange flowers, lack of milky sap, alternate leaves, and pubescence. Four species have been featured previously in this series of articles: Four-Leaved Milkweed (A. quadrifolia), White or Red-ring Milkweed (A. variegata), Whorled Milkweed (A. verticillata), and Green Milkweed (A. viridiflora).

Article and photographs by ANPS member Sid Vogelpohl

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