Asclepias cordifolia
Asclepias vestita
heart-leaf milkweed, purple milkweed
woolly milkweed, wooly milkweed
1–20, ascending to spreading, unbranched, 25–100 cm, glabrous, glaucous, rhizomes absent.
1–20, prostrate to decumbent or ascending, rarely branched, 25–90 cm, tomentose, not glaucous, rhizomes absent.
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, petiolate, with 0 or 1 stipular colleter on each side of petiole;
petiole 3–10 mm, tomentose;
blade elliptic or oval to lanceolate or ovate, 8–20 × 2–10 cm, chartaceous, base cuneate to rounded or cordate, margins entire, apex acute to attenuate or acuminate, mucronate, venation eucamptodromous to faintly brochidodromous, surfaces densely to thinly tomentose, 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.
extra-axillary at upper nodes, sometimes appearing terminal, sessile or pedunculate, 19–45-flowered;
peduncle 0–3.5 cm, densely tomentose, with 1 caducous bract at the base of each pedicel.
16–37 mm, sparsely pilose.
15–35 mm, densely tomentose.
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 pendent;
calyx lobes elliptic, 5–6 mm, apex acute, densely tomentose;
corolla green to pinkish purple, lobes reflexed, sometimes with spreading tips, oval, 6–9 mm, apex acute, densely tomentose abaxially, papillose at base adaxially;
gynostegial column 1–1.5 mm;
fused anthers dark brown, truncately obconic, 1.5–2 mm, wings right-triangular, closed, apical appendages ovate;
corona segments cream to dark pink, sessile, conduplicate, dorsally rounded, 3–3.5 mm, equaling or slightly exceeding style apex, apex obtuse, oblique, margin with proximal tooth, glabrous, internal appendage falcate, slightly exserted, glabrous;
style apex shallowly depressed, cream.
ovate, 8–9 × 5–7 mm, margin not winged, faces reticulate-rugulose;
coma 3–3.5 cm.
ovate, 10–12 × 7–10 mm, margin very narrowly winged, faces smooth;
coma 2–2.5 cm.
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, ovoid, 5–6.5 × 2–2.5 cm, apex apiculate to acuminate, longitudinally ridged, tomentulose.
= 22.
= 22.
Asclepias cordifolia
Asclepias vestita
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.)
W. L. Jepson (1923–1925) and R. E. Woodson Jr. (1954) segregated southern populations (Inyo, Kern, Los Angeles, San Bernardino, and Ventura counties) from northern populations (Fresno, Madera, Mariposa, Merced, Monterey, San Benito, San Joaquin, and San Luis Obispo counties) as varieties or subspecies. Of their distinguishing characters, only flower color is consistently different between these segments of the range: northern populations have pale green corollas with at most a pink tinge, whereas southern populations have pale burgundy to red-violet corollas. There is a tendency for plants in southern populations to be smaller and become more evidently glabrate late in the season, but more robust and hairier plants can also be found in the south. Further research may support recognition of distinct taxa for these populations, but they are not recognized here. Asclepias vestita is similar to co-occurring A. californica in the absence of flowers or fruits, but plants of A. vestita tend to be more prostrate and compact and the leaves tend to be broader towards the base and more quickly glabrate.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
