Asclepias obovata |
Asclepias solanoana |
|
---|---|---|
pineland milkweed |
prostrate milkweed, serpentine milkweed |
|
Habit | Herbs. | Herbs. |
Stems | 1 (rarely more), erect to spreading, unbranched, 40–70(–200) cm, densely hirtellous to velutinous, not glaucous, rhizomes absent. |
1–15, prostrate, unbranched (rarely branched), 15–40 cm, densely puberulent with curved trichomes to tomentose, 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, stipular colleters absent; petiole 5–10 mm, densely puberulent with curved trichomes; blade ovate to nearly orbiculate, 3.5–6 × 3–4 cm, subsucculent, base obtuse to cordate, margins entire, apex obtuse to acute or rounded, venation eucamptodromous, surfaces pilosulous, more densely so abaxially, especially on veins, becoming glabrate adaxially, margins inconspicuously ciliate, 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 and extra-axillary, pedunculate, 20–55-flowered; peduncle 1.5–9 cm, tomentose, with 1 caducous bract at the base of each pedicel. |
Pedicels | 10–12 mm, densely hirtellous to velutinous. |
10–13 mm, tomentose to pilose. |
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 spreading; calyx lobes lanceolate, 2–3 mm, apex acute, pilose to tomentose; corolla pale pink to red, lobes reflexed with spreading tips, oval, 5–6 mm, apex acute, glabrous; gynostegium sessile; fused anthers yellow to brown or green, broadly barrel-shaped, 1.5–2 mm, wings deltoid, widest at middle, closed, apical appendages ovate; corona segments pinkish cream to cream, subsessile, conduplicate, dorsally rounded, spreading away from anthers, 2–3 mm, greatly exceeded by style apex, apex truncate, glabrous, internal appendage absent; style apex shallowly depressed, cream to green. |
Seeds | broadly ovate, 8–9 × 6–7 mm, margin winged, faces smooth; coma 2–5 cm. |
ovate, 6–8 × 5–6 mm, margin very narrowly winged, faces rugulose; coma 2–2.5 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 (at least until maturity), lance-ovoid, 6–10 × 2–3 cm, apex obtuse to acuminate, longitudinally ridged, pilosulose or tomentulose to glabrate. |
Asclepias obovata |
Asclepias solanoana |
|
Phenology | Flowering May–Sep; fruiting Jul–Oct. | Flowering (Apr–)May–Aug; fruiting Jun–Jul. |
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, streamsides, canyons, barrens, serpentine, rocky and deep soils, chaparral, cypress and mixed-conifer woodlands, pine and mixed-conifer forests, meadows. |
Elevation | 0–200 m. (0–700 ft.) | 200–2000 m. (700–6600 ft.) |
Distribution |
AL; AR; FL; GA; LA; MS; OK; SC; TX
|
CA
|
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 solanoana is a delightful and unique milkweed that is endemic to rugged, serpentine barrens in the northern Coast Range of California. The plants hug the ground, the stems seeming to crawl outward propelled by the highly unusual metallic, grayish or bluish green, ovate leaves. Bright pinkish rose balls of floral buds are held above, and are followed by variegated spheres of cream, pink, green, and brown flowers with a vague resemblance to heads of Abronia (Nyctaginaceae). It is often the only conspicuous plant species on highly exposed, south-facing slopes. S. P. Lynch (1977) documented Hymenoptera (carpenter bees, Xylocopa, bumblebees, Bombus, and honeybees, Apis) to be the main pollinators of A. solanoana. It is considered threatened by extractive industries and recreation at some sites. A naturally occurring population has been reported from southern Oregon and needs confirmation. (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 purpurascens, Solanoa purpurascens | |
Name authority | Elliott: Sketch Bot. S. Carolina 1: 321. (1817) | Woodson: Ann. Missouri Bot. Gard. 28: 207. (1941) |
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