Asclepias curassavica |
Asclepias meadii |
|
|---|---|---|
|
blood flower, bloodflower milkweed, hierba de la cucaracha, tropical milkweed, wild ipecacuanha |
Mead's milkweed |
|
| Habit | Subshrubs or herbs. | Herbs. |
| Stems | 1–several, erect, sparsely to moderately branched, 30–150 cm, minutely pilosulous in a line to glabrate, not glaucous, rhizomes absent. |
1 (rarely 2), erect, unbranched, 20–80 cm, glabrous, glaucous, rhizomatous. |
| Leaves | persistent or gradually caducous from the base, opposite, petiolate, with 1 or 2 stipular colleters on each side of petiole on a ciliate interpetiolar ridge; petiole 4–25 mm, puberulent with curved trichomes in a line to glabrate; blade elliptic or oval to linear, 4–18 × 0.3–4.5 cm, membranous, base cuneate, margins entire, apex acute to acuminate to attenuate, venation eucamptodromous to faintly brochidodromous, surfaces sparsely puberulent with curved trichomes on veins abaxially, sparsely puberulent with curved trichomes on veins to glabrate adaxially, margins ciliate, laminar colleters absent. |
opposite, sessile, with 1 stipular colleter on each side of petiole; blade ovate to lanceolate, 4.5–10 × 1–5 cm, chartaceous, base rounded to obtuse, margins entire, apex acute, venation brochidodromous, surfaces glabrous, glaucous, margins inconspicuously ciliate, laminar colleters absent. |
| Inflorescences | extra-axillary, pedunculate, 5–22-flowered; peduncle 0.5–8 cm, puberulent with curved trichomes in a line, with 1 caducous bract at the base of each pedicel. |
terminal, rarely branched, pedunculate, 7–19-flowered; peduncle (0–)3–10 cm, sparsely pilosulous to glabrate, glaucous, with 1 caducous bract at the base of each pedicel. |
| Pedicels | 7–20 mm, puberulent with curved trichomes. |
11–20 mm, pilosulous. |
| Flowers | erect; calyx lobes linear-lanceolate, 3–4 mm, apex acute, puberulent with curved trichomes; corolla red, sometimes yellow in throat (to wholly orange or yellow in cultivars), lobes reflexed with spreading tips, elliptic to oval, 6–9 mm, apex acute, glabrous abaxially, minutely papillose at base adaxially; gynostegial column 2–2.5 mm; fused anthers yellowish green to tan, cylindric, 1.5–2 mm, wings narrowly right-triangular, closed, apical appendages deltoid; corona segments yellow to orange, stipitate, tubular, dorsally somewhat flattened, 3.5–4 mm, exceeding style apex, apex obtuse to acute, glabrous, internal appendage falcate, exserted, arching over style apex, glabrous; style apex shallowly depressed, yellow. |
pendent; calyx lobes narrowly lanceolate, 4–5 mm, apex acute, pilosulous; corolla green to greenish cream, sometimes tinged red, lobes reflexed with spreading tips, oval, 7–9 mm, apex acute, glabrous; gynostegial column 1.5–1.8 mm, fused anthers green, truncately obconic, 2–2.5 mm, wings right-triangular, closed, apical appendages ovate; corona segments green to yellowish green or greenish cream, sessile, conduplicate, dorsally rounded, 4–5.5 mm, greatly exceeding style apex, base saccate, apex obtuse, emarginate, slightly flared, glabrous, internal appendage falcate, exserted, sharply inflexed towards style apex, glabrous; style apex shallowly depressed, green. |
| Seeds | ovate, 6–7 × 4–5 mm, margin winged, faces minutely rugulose to smooth; coma 2.5–3 cm. |
ovate, 6–7 × 4–5 mm, winged, faces coarsely papillose; coma 3–4.5 cm. |
| Follicles | erect on straight pedicels, fusiform, 6–10 × 0.5–1.2 cm, apex acuminate to attenuate, smooth, glabrous. |
erect on upcurved pedicels, narrowly fusiform, 7–14 × 0.9–1.6 cm, apex long-acuminate, smooth to minutely rugulose, puberulent with curved trichomes. |
| 2n | = 22. |
|
Asclepias curassavica |
Asclepias meadii |
|
| Phenology | Flowering and fruiting year-round. | Flowering May–Jun(–Jul); fruiting Jun–Aug. |
| Habitat | Disturbed areas, fields, orchards, and gardens, canal banks, ditches, streamsides, wet prairies, marshes, swamps, coastal dunes, sandy soils. | Dry, upland prairies, chert-lime glades. |
| Elevation | 0–100 m. [0–300 ft.] | 100–500 m. [300–1600 ft.] |
| Distribution |
CA; FL; LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America; introduced also to Old World tropics]
|
IA; IL; IN; KS; MO; WI
|
| Discussion | Asclepias curassavica is the only non-native Asclepias species naturalized in the flora area. It is very commonly cultivated, originally for its strikingly colored flowers and their attraction of Lepidoptera and Hymenoptera. Recently, they have been valued also as a host plant for monarch butterflies. Cultivars with pure orange or pure yellow flowers are readily available. The species develops rapidly from seed and can be grown as an annual (in the horticultural sense) anywhere in the region. Though often described as an annual, like all species of Asclepias, it has a perennial habit. It may persist through mild winters at least as far north as Oklahoma but has only become established in frost-free areas of the southern United States. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
With respect to historical range reduction and potential threats, Asclepias meadii is the most endangered North American milkweed species and is considered to be of conservation concern in each of the states in which it occurs. Nearly all of the viable populations are now restricted to Missouri and eastern Kansas; many of these are found in hay meadows, in which fruit maturation does not occur. Asclepias meadii is endemic to the highly-impacted tallgrass prairie ecoregion and is thought to be rare as a result of habitat loss. Consequently, concern for the continued existence of this species can be considered emblematic of concern for the tallgrass prairie as a whole. Active recovery efforts have achieved limited success, with newly established populations experiencing high mortality and slow growth of transplants. It has been re-introduced to Indiana and Wisconsin, but long-term survival of these populations is uncertain. The sessile, glaucous leaves and pendent umbels on a long peduncle suggest a diminutive version of A. elata; however, these species do not appear to be closely related (Fishbein et al. 2011). The terminal inflorescence of pendent umbels is unique among tallgrass prairie milkweeds. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
| Parent taxa | ||
| Sibling taxa | ||
| Name authority | Linnaeus: Sp. Pl. 1: 215. (1753) | Torrey ex A. Gray: Manual ed. 2, 704. (1856) |
| Source | FNA vol. 14. | FNA vol. 14. |
| Web links | ||