Asclepias obovata |
Asclepias cutleri |
|
---|---|---|
pineland milkweed |
Cutler's milkweed |
|
Habit | Herbs. | Herbs. |
Stems | 1 (rarely more), erect to spreading, unbranched, 40–70(–200) cm, densely hirtellous to velutinous, not glaucous, rhizomes absent. |
1–5, erect to ascending, unbranched, 7–20 cm, strigose to pilose, 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. |
alternate, sessile, stipular colleters absent; blade linear to filiform, 2.5–8 × 0.1–0.2 cm, membranous, base cuneate, margins entire, apex acute, mucronate, venation obscure, surfaces strigose to glabrate, margins sparsely ciliate to glabrate, 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. |
extra-axillary at upper nodes, appearing terminal, sessile or pedunculate, 2–5-flowered (appearing greater because umbels are in close proximity); peduncle 0–0.1 cm, densely strigose, bracts few. |
Pedicels | 10–12 mm, densely hirtellous to velutinous. |
6–15 mm, strigose 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 lance-ovate, 1.5–2 mm, apex acute, strigose to pilose; corolla red-violet, lobes reflexed or sometimes spreading, oval, 2.5–4 mm, apex acute, pilose abaxially, glabrous adaxially; gynostegial column 0.5 mm; fused anthers brown, cylindric, 1.5–2 mm, wings right-triangular, apical appendages ovate; corona segments white, sessile, cupulate, 1.5 mm, exceeded by style apex, base saccate, apex truncate with a proximal tooth on each side, glabrous, internal appendage lingulate, barely exserted from cavity, glabrous; style apex shallowly depressed, pink to reddish. |
Seeds | broadly ovate, 8–9 × 6–7 mm, margin winged, faces smooth; coma 2–5 cm. |
oval, 9–11 × 4–6 mm, margin corky, winged, erose, faces ruglose-papillate, minutely hirtellous; coma 1.5 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. |
pendulous on spreading to declined pedicels, lance-ovoid, 3–6 × 0.5–0.8 cm, apex attenuate, smooth, faintly striate, strigose. |
Asclepias obovata |
Asclepias cutleri |
|
Phenology | Flowering May–Sep; fruiting Jul–Oct. | Flowering Apr–Jun; fruiting May–Jun. |
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. | Sand dunes, sandy soils, grasslands, shrubby grasslands. |
Elevation | 0–200 m. (0–700 ft.) | 1400–1700 m. (4600–5600 ft.) |
Distribution |
AL; AR; FL; GA; LA; MS; OK; SC; TX
|
AZ; UT |
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 cutleri is an edaphic endemic, limited to deep red, pink, and orange sand deposits developed on geologic units of sedimentary origin of the Colorado Plateau. Its range is restricted to Apache, Coconino, and Navajo counties in Arizona and Grand and San Juan counties in Utah. The majority of occurrences are on the Navajo reservation. A report from San Juan County, New Mexico, needs confirmation. Although rarely collected, it is highly cryptic due to its small stature and slender habit, and it is probably more common than it appears in its preferred habitat. The herbage has a bluish hue when fresh that turns green on drying, similar to A. brachystephana and A. cryptoceras. It is often erroneously described to be an annual because the very deep roots are almost never extricated, and the slender subterranean stem appears to be the root. Paired fruits from a single flower appear to be unusually common compared to other species of Asclepias. The flowers are remarkably similar to those of A. brachystephana and the so-called dwarf milkweeds, A. eastwoodiana, A. ruthiae, A. uncialis, and the sympatric A. sanjuanensis, but these species are only distantly related to A. cutleri (M. Fishbein et al. 2011). (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) | Woodson: Ann. Missouri Bot. Gard. 26: 263, fig. 2. (1939) |
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