Asclepias obovata |
Asclepias hypoleuca |
|
---|---|---|
pineland milkweed |
mahogany milkweed, talayote |
|
Habit | Herbs. | Herbs. |
Stems | 1 (rarely more), erect to spreading, unbranched, 40–70(–200) cm, densely hirtellous to velutinous, not glaucous, rhizomes absent. |
1 (rarely 2 or 3), erect, unbranched, 25–100 cm, puberulent with curved trichomes to pilosulous, 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, petiolate, with 1 stipular colleter on each side of petiole; petiole 2–6 mm, puberulent with curved trichomes to pilosulous; blade ovate or lanceolate to oblong, elliptic, or oval, 5.5–11.5 × 1–5 cm, chartaceous, base cuneate or obtuse to truncate, margins entire, apex obtuse to rounded, mucronate, venation eucamptodromous, surfaces tomentose abaxially, pilosulous or tomentulose to glabrate adaxially, margins ciliate, 8–12 laminar colleters. |
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 and extra-axillary, pedunculate, 12–35-flowered; peduncle 3.5–10.5 cm, puberulent with curved trichomes to tomentulose, with 1 caducous bract at the base of each pedicel. |
Pedicels | 10–12 mm, densely hirtellous to velutinous. |
15–21 mm, densely puberulent with curved trichomes or pilosulous to tomentulose. |
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. |
erect to pendent; calyx lobes lanceolate, 3–4 mm, apex acute, pilose; corolla green, sometimes red-tinged abaxially, deep maroon to greenish red or green adaxially, lobes reflexed, tips usually spreading, oblong to elliptic, 8–10 mm, apex acute, pilosulous abaxially, glabrous adaxially; gynostegial column 1–1.5 mm; fused anthers brown, broadly cylindric, 2–2.5 mm, wings right-triangular, open at tip, apical appendages ovate, erose; corona segments deep maroon to greenish red or yellowish green, subsessile, conduplicate, 7–9 mm, greatly exceeding style apex, apex truncate, spreading and long-tapering with a proximal tooth on each side, glabrous, internal appendage absent or a low crest, glabrous; style apex shallowly depressed, green. |
Seeds | broadly ovate, 8–9 × 6–7 mm, margin winged, faces smooth; coma 2–5 cm. |
ovate, 6–7 × 4–5 mm, margin winged, faces minutely rugulose; coma 3–3.5 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 upcurved pedicels, fusiform, 9–11.5 × 1.2–1.4 cm, apex long-attenuate, smooth, sometimes faintly striate, pilosulous to tomentulose. |
Asclepias obovata |
Asclepias hypoleuca |
|
Phenology | Flowering May–Sep; fruiting Jul–Oct. | Flowering Jun–Sep; fruiting Aug–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. | Slopes, flats, lake shores, streamsides, granite, gneiss, andesite, rocky soils, pine, pine-oak, oak, and mixed-conifer forests. |
Elevation | 0–200 m. (0–700 ft.) | 1900–2800 m. (6200–9200 ft.) |
Distribution |
AL; AR; FL; GA; LA; MS; OK; SC; TX
|
AZ; NM; Mexico (Chihuahua, Sonora)
|
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.) |
Asclepias hypoleuca grows at higher elevations in the sky-island mountain ranges than any other milkweed. It has been documented from the Chiricahua, Huachuca, Rincon, Santa Catalina, Santa Rita, and White mountain ranges in Arizona (Cochise, Pima, and Santa Cruz counties) and the Mogollon Mountains and Black Range in New Mexico (Catron and Grant counties). Because of its limited, high-elevation distribution, and the threats of changing climate, its conservation status in the flora area merits assessment. The bicolored leaves exhibit coloration similar to co-occurring silverleaf oak (Quercus hypoleucoides). (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 | ||
Synonyms | Gomphocarpus hypoleucus | |
Name authority | Elliott: Sketch Bot. S. Carolina 1: 321. (1817) | (A. Gray) Woodson: Ann. Missouri Bot. Gard. 28: 206. (1941) |
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