Asclepias cordifolia
Asclepias lanuginosa
heart-leaf milkweed, purple milkweed
asclépiade laineuse, side-cluster milkweed, small-green milkweed, woolly milkweed
1–20, ascending to spreading, unbranched, 25–100 cm, glabrous, glaucous, rhizomes absent.
1 or 2 (rarely more), erect to spreading, unbranched, 7–20 cm, densely hirtellous to pilose, not glaucous, rhizomatous.
opposite, sessile, stipular colleters absent;
blade ovate to lanceolate, 3.5–11 × 1.8–8 cm, chartaceous, base cordate, clasping, margins entire, apex acute, mucronate, venation brochidodromous to eucamptodromous, surfaces glabrous, glaucous, margins minutely ciliate, laminar colleters absent.
opposite or alternate, petiolate, with 1 stipular colleter on each side of petiole;
petiole 1–2 mm, hirtellous;
blade oblong or lanceolate to narrowly lanceolate, 4–8 × 0.5–2.7 cm, chartaceous, base cuneate to rounded or subcordate, margins entire, apex acute to obtuse, venation eucamptodromous to reticulodromous, surfaces hirtellous, margins ciliate, laminar colleters absent.
terminal, branched, sometimes also extra-axillary at upper nodes, pedunculate, 5–20-flowered;
peduncle 0.3–6.5 cm, apically sparsely pilose to glabrate, with few bracts.
terminal, usually solitary, pedunculate, 17–50-flowered (rarely more);
peduncle 1–3 cm, densely hirtellous to pilose, with 1 caducous bract at the base of each pedicel.
16–37 mm, sparsely pilose.
9–13 mm, hirtellous to pilose.
erect to pendent;
calyx lobes elliptic to lanceolate, 3–5 mm, apex acute, pilose;
corolla red-violet, lobes reflexed with spreading tips, oval, 6–7 mm, apex acute, glabrous;
gynostegial column 1–1.5 mm;
fused anthers brown, cylindric, 1.5–2 mm, wings right-triangular, open at tip, apical appendages deltoid;
corona segments white, tinged pink to red-violet at base, sessile, tubular, 2–3 mm, exceeded by style apex, base saccate, apex truncate, oblique, glabrous, internal appendage absent;
style apex shallowly depressed, pink to red-violet.
erect to spreading;
calyx lobes narrowly lanceolate, 1.5–2 mm, apex acute, hirtellous;
corolla greenish cream, sometimes purple-tinged, lobes reflexed, oblong, 3–5 mm, apex acute, glabrous;
gynostegial column 0–0.2 mm;
fused anthers green, broadly cylindric, 1.5–2 mm, wings triangular, widest below middle, closed, apical appendages ovate;
corona segments cream to greenish cream, sessile, chute-shaped, margins incurved, appressed to column, 2–3.5 mm, exceeded by style apex, base saccate, apex rounded, glabrous, internal appendage absent or obscure, glabrous;
style apex shallowly depressed, green to greenish cream.
ovate, 8–9 × 5–7 mm, margin not winged, faces reticulate-rugulose;
coma 3–3.5 cm.
ovate, 6–7 × 4–5 mm, faces minutely rugulose;
comose.
erect on upcurved pedicels, lance-ovoid, 7.5–10.5 × 1.5–1.8 cm, apex long-acuminate, smooth, glabrous, glaucous.
erect on upcurved pedicels, fusiform, 8–10 × 0.8–1.5 cm, apex long-acuminate, smooth, hirtellous to pilose.
= 22.
= 22.
Asclepias cordifolia
Asclepias lanuginosa
Fresh leaves and stems of Asclepias cordifolia are often slightly or strongly colored bluish, grayish, or purplish. This is one of the few American species of Asclepias with cavitate corona segments that lack adaxial appendages. Such species were segregated along with diverse African species in Gomphocarpus R. Brown, a polyphyletic segregate (M. Fishbein et al. 2011; D. Chuba et al. 2017). Asclepias cordifolia is a distinctive species unlike any other within its range. It is phylogenetically and geographically isolated, although not highly derived morphologically. In Nevada, A. cordifolia is restricted to the Sierra Nevada, in Carson City, Douglas, and Washoe counties. Its range extends to northern California and southwestern Oregon.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Asclepias lanuginosa is highly cryptic due to its small stature and early flowering. It resembles a short, hirtellous form of A. viridiflora. In addition to the differences in vestiture, A. lanuginosa can be distinguished from that species by the terminal inflorescence and the cream-colored corona segments. Due to severe habitat loss in the tallgrass prairie region, A. lanuginosa has apparently declined and is of conservation concern over much of its range, that is, in Illinois, Iowa, Kansas, North Dakota, South Dakota, and Wisconsin. It is more secure in Nebraska, but an overall re-assessment of the status of this species is warranted. The only report from Montana is from the “Yellowstone expedition,” which may not have been collected in the state. R. E. Woodson Jr. (1954) considered A. lanuginosa Kunth (a later homonym) to be the correct name for a Mexican species, A. otarioides E. Fournier. He soon realized that A. lanuginosa Nuttall has priority, but prior usage and his extensive annotations produced lingering confusion over the correct name of the Mexican species. Torrey’s replacement name for this species, A. nuttalliana, is illegitimate, as it was superfluous on publication.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
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WildflowerSearch
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USDA Plants Database
IL Wildflowers
KS Wildflowers
MN Wildflowers
