Asclepias cordifolia
Asclepias cutleri
heart-leaf milkweed, purple milkweed
Cutler's milkweed
1–20, ascending to spreading, unbranched, 25–100 cm, glabrous, glaucous, rhizomes absent.
1–5, erect to ascending, unbranched, 7–20 cm, strigose to pilose, 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.
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.
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, 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.
16–37 mm, sparsely pilose.
6–15 mm, strigose 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 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.
ovate, 8–9 × 5–7 mm, margin not winged, faces reticulate-rugulose;
coma 3–3.5 cm.
oval, 9–11 × 4–6 mm, margin corky, winged, erose, faces ruglose-papillate, minutely hirtellous;
coma 1.5 cm.
erect on upcurved pedicels, lance-ovoid, 7.5–10.5 × 1.5–1.8 cm, apex long-acuminate, smooth, glabrous, glaucous.
pendulous on spreading to declined pedicels, lance-ovoid, 3–6 × 0.5–0.8 cm, apex attenuate, smooth, faintly striate, strigose.
= 22.
Asclepias cordifolia
Asclepias cutleri
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 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.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
SW CO Wildflowers
