Asclepias obovata |
Asclepias cinerea |
|
---|---|---|
pineland milkweed |
ashy milkweed, Carolina milkweed |
|
Habit | Herbs. | Herbs. |
Stems | 1 (rarely more), erect to spreading, unbranched, 40–70(–200) cm, densely hirtellous to velutinous, not glaucous, rhizomes absent. |
1, erect, unbranched (rarely branched), 20–100 cm, minutely puberulent in a line with curved trichomes to glabrate, not glaucous, rhizomes absent. |
Leaves | opposite, petiolate, with 1 or 2 stipular colleters on each side of petiole; petiole 1–4 mm, densely hirtellous to velutinous; blade oblong or elliptic to obovate or ovate, 4–9 × 1–3.5 cm, subcoriaceous, base rounded or truncate to cordate, margins sometimes crisped, apex acute to truncate, sometimes emarginate, often mucronate, venation brochidodromous, surfaces densely hirtellous to velutinous abaxially, hirtellous adaxially, margins ciliate, 8–12 laminar colleters. |
opposite, sessile, with 1 or 2 stipular colleters on each side of leaf base; blade filiform, 2–9 × 0.1–0.15 cm, membranous, base cuneate, margins entire, apex acute, mucronate, venation obscure, surfaces glabrous, laminar colleters absent. |
Inflorescences | extra-axillary, sometimes also appearing terminal, sessile or pedunculate, 7–31-flowered; peduncle 0–0.5 cm, densely hirtellous to velutinous, with 1 caducous bract at the base of each pedicel. |
terminal, branched, and extra-axillary at upper nodes, pedunculate, 2–8-flowered; peduncle 0.5–1.7 cm, puberulent with curved trichomes on 1 side, with 1 caducous bract at the base of each pedicel. |
Pedicels | 10–12 mm, densely hirtellous to velutinous. |
10–25 mm, minutely puberulent with curved trichomes on 1 side. |
Flowers | erect to pendent; calyx lobes elliptic, 5–6 mm, apex acute, densely hirtellous; corolla green, sometimes tinged reddish or bronze, lobes reflexed, sometimes with spreading tips, elliptic, 7–9 mm, apex acute, glabrous abaxially, minutely papillose at base adaxially; gynostegial column 1–1.5 mm; fused anthers green, obconic, 2.5–4 mm, wings right-triangular, open at base, apical appendages broadly ovate; corona segments bronze to yellow, often tinged red, sometimes apically cream or pale, stipitate, tubular, somewhat flattened laterally, flared at base, 5–8 mm, greatly exceeding style apex, apex rounded, flared, glabrous, internal appendage falcate, exserted, sharply incurved over style apex, glabrous; style apex shallowly depressed, green. |
spreading to pendent; calyx lobes lanceolate, 1.5–2 mm, apex acute, glabrous; corolla cream, tinged gray, pink, or purple, faintly striate, lobes reflexed with spreading tips, elliptic, 4–5 mm, apex acute to obtuse, glabrous; gynostegial column 0–0.5 mm; fused anthers green, cylindric, 1.5–2 mm, wings narrowly right-triangular, open, apical appendages deltate; corona segments cream, tinged gray, pink, or purple, sessile, conduplicate, dorsally flattened, 2–3 mm, equaling style apex, apex truncate with a proximal tooth on each side, glabrous, internal appendage a laterally flattened, included crest, glabrous; style apex shallowly depressed, white. |
Seeds | broadly ovate, 8–9 × 6–7 mm, margin winged, faces smooth; coma 2–5 cm. |
ovate, 6–7 × 4–5 mm, margin thickly winged, faces sparsely papillose; coma 2.5–3 cm. |
Follicles | erect on upcurved pedicels, narrowly to broadly fusiform, 7.5–12.5 × 1.5–2.5 cm, apex acuminate, smooth, densely hirtellous to velutinous. |
erect on straight pedicels, fusiform, 8–12 × 0.3–0.7 cm, apex long-attenuate, smooth, glabrous. |
Asclepias obovata |
Asclepias cinerea |
|
Phenology | Flowering May–Sep; fruiting Jul–Oct. | Flowering May–Sep(–Nov); fruiting Jun–Sep. |
Habitat | Hills, slopes, flats, ridges, sandhills, ditches, seeps, bogs, sandstone, sandy, rocky, silty, and clay soils, pine flatwoods, pine savannas, pine, pine-oak, and bottomland hardwood forests, prairies, often following fires. | Ridges, flats, fields, sandstone, sandy soils, wet to dry pine flatwoods, barrens and savannas, pine-oak forest, often recently burned, bogs, swamps. |
Elevation | 0–200 m. (0–700 ft.) | 0–200 m. (0–700 ft.) |
Distribution |
AL; AR; FL; GA; LA; MS; OK; SC; TX
|
AL; FL; GA; SC
|
Discussion | Asclepias obovata is a common milkweed of seasonally wet, sandy soils in pine woodlands of the Gulf Coastal Plain and (rarely) the southern Atlantic Coastal Plain. It is rare and considered to be of conservation concern in Arkansas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Similarities between Asclepias cinerea and A. feayi are discussed under the latter species. Asclepias cinerea inhabits flatwoods mostly north of the range of A. feayi, co-occurring only in Clay County as far as is known. Asclepias cinerea is sympatric with another similar species, A. viridula, across northern Florida. That species tends to grow in wetter woods and meadows than A. cinerea. In flower, they are easily distinguished by the spreading to pendent flowers, ashy lavender corollas, and corona segments with included, crestlike appendages of A. cinerea (versus erect to spreading flowers, green to brownish corollas, and corona segments with exerted, falcate appendages of A. viridula). Asclepias cinerea barely enters southeastern Alabama (Covington, Geneva, and Houston counties), and the species is considered to be of conservation concern in that state. Emergence and flowering of this species appears to be stimulated by precipitation events and/or fire. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 14. | FNA vol. 14. |
Parent taxa | Apocynaceae > Asclepias | Apocynaceae > Asclepias |
Sibling taxa | ||
Name authority | Elliott: Sketch Bot. S. Carolina 1: 321. (1817) | Walter: Fl. Carol., 105. (1788) |
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