Asclepias cordifolia
Asclepias speciosa
heart-leaf milkweed, purple milkweed
asclépiade belle, showy milkweed
1–20, ascending to spreading, unbranched, 25–100 cm, glabrous, glaucous, rhizomes absent.
1–few, erect, unbranched (rarely branched), 30–125 cm, tomentose to puberulent with curved trichomes, 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, petiolate, with 1 or 2 stipular colleters on each side of petiole, sometimes also in axil;
petiole 4–12 mm, tomentose to pilose;
blade lanceolate or ovate to oblong, 6–20 × 2–14 cm, chartaceous, base rounded to truncate or cordate, margins entire, apex acute to obtuse, sometimes mucronate, venation faintly brochidodromous, surfaces tomentose to pilose, margins ciliate, 6–32 laminar colleters.
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, pedunculate, 3–34-flowered;
peduncle 1–10 cm, densely tomentose, with 1 caducous bract at the base of each pedicel.
16–37 mm, sparsely pilose.
13–30 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, 4–8 mm, apex acute, tomentose;
corolla dark pink (rarely pale), lobes reflexed with spreading tips, elliptic, 9–12 mm, apex acute, densely pilose abaxially, hirtellous at base adaxially;
gynostegial column 0.5–1 mm;
fused anthers green and brown, truncately obconic, 2.5–3 mm, wings right-triangular, open, widely so at base, apical appendages deltoid;
corona segments pale pink to nearly cream, sessile, scoop-shaped, 9–15 mm, exceeding style apex, apex truncate with proximal tooth on each side and long-attenuate, flared, glabrous, internal appendage subulate, exserted, sharply inflexed over style apex, glabrous;
style apex shallowly depressed, green to cream or pink.
ovate, 8–9 × 5–7 mm, margin not winged, faces reticulate-rugulose;
coma 3–3.5 cm.
ovate, 7–9 × 4–5 mm, margin winged, faces rugulose;
coma 2.5–3 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, lance-ovoid, (5–)9–12 × 2–3 cm, apex long-attenuate, muricate or smooth, densely tomentose.
= 22.
= 22.
Asclepias cordifolia
Asclepias speciosa
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 speciosa is the western counterpart of A. syriaca; both are broad-leaved species with large umbels of pinkish flowers. The distinctive, large, tapering corona segments, which form the broadest corona span of any American species of Asclepias, immediately distinguish A. speciosa from A. syriaca. These species hybridize extensively from Minnesota and southern Manitoba to Kansas, blurring the distinctions in the zone of contact, which corresponds roughly to the transition from tallgrass to mixed-grass prairie (R. P. Adams et al. 1987b). Not every individual in this zone can be readily assigned to one species or the other. This is the most extensive hybrid zone in North American Asclepias. These hybrids have also been documented in Illinois, far to the east of the contact zone. Possible hybrids with A. eriocarpa and A. hallii in California are discussed under those species. Outside of its contiguous range in the West, A. speciosa is known from a few sporadic, mostly historical records from Illinois, Michigan, Missouri, and Wisconsin. Most, if not all, of these records represent adventive, ephemeral outposts from the native range.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
IL Wildflowers, 
KS Wildflowers, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria, 
SW CO Wildflowers, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
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