Asclepias speciosa
Asclepias nummularia
asclépiade belle, showy milkweed
tuft milkweed
1–few, erect, unbranched (rarely branched), 30–125 cm, tomentose to puberulent with curved trichomes, not glaucous, rhizomatous.
1–5, erect, unbranched, 6–15 cm, taller on vegetative or post-reproductive plants, densely tomentose to glabrate, not glaucous, rhizomes 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.
opposite, petiolate, with 1 stipular colleter on either side of petiole;
petiole 3–4 mm, tomentose to glabrate;
blade orbiculate to obovate or oblate, 1.5–3.2 × 1.7–4 cm, much larger on vegetative or post-reproductive stems, subsucculent, base rounded to cordate, margins entire, apex truncate or emarginate to rounded or obtuse, venation eucamptodromous, surfaces tomentose to glabrate, laminar colleters 0–10.
extra-axillary, pedunculate, 3–34-flowered;
peduncle 1–10 cm, densely tomentose, with 1 caducous bract at the base of each pedicel.
terminal, sometimes also extra-axillary, pedunculate, 5–28-flowered;
peduncle 2.7–6 cm, tomentose, with 1 bract at the base of each pedicel.
13–30 mm, densely tomentose.
12–20 mm, densely pilosulous to tomentulose.
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.
erect;
calyx lobes ovate to lanceolate, 1.5–2.5 mm, apex acute, pilose to tomentulose;
corolla pinkish violet to tan, striate, lobes reflexed, oval, 4–5 mm, apex acute, glabrous abaxially, minutely papillate at base adaxially;
gynostegial column 0.2–0.5 mm;
fused anthers brown, cylindric, 1–1.5 mm, wings curved, closed, apical appendages ovate, erose;
corona segments white apically, red-violet basally, sessile, conduplicate, dorsally rounded, 2.5–3 mm, equaling or exceeding style apex, apex truncate, glabrous, internal appendage falcate, exserted, sharply inflexed over style apex, glabrous;
style apex shallowly depressed, cream to pink.
ovate, 7–9 × 4–5 mm, margin winged, faces rugulose;
coma 2.5–3 cm.
broadly ovate, 6–7 × 4–5 mm, margin winged, corky, erose at chalazal end, faces papillose-rugulose, hirtellous;
coma 1.5–2.5 cm.
erect on upcurved pedicels, lance-ovoid, (5–)9–12 × 2–3 cm, apex long-attenuate, muricate or smooth, densely tomentose.
erect on upcurved pedicels, lance-ovoid, 4–7.5 × 1.2–1.5 cm, apex long-acuminate, smooth, tomentose.
= 22.
Asclepias speciosa
Asclepias nummularia
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.)
Asclepias nummularia is the only milkweed in the flora area with small stature and obovate to orbiculate leaves that are bluish under dense tomentum until late in the season. The plants often bear an uncanny resemblance to tiny cabbages. Fruit set may fail across broad regions in some years, perhaps due to drought, although the adequacy of pollination in this species has not been studied. Unlike many species of Asclepias, post-reproductive and non-reproductive plants of A. nummularia often persist until frost. Coupled with the early flowering of this species, vegetative plants are observed and collected far more often than reproductive ones. Some plants persisting into the fall months have much larger leaves and longer stems, especially in shady or moist habitats; these have often been mistaken for A. latifolia, the range of which only barely overlaps that of A. nummularia in Grant County, New Mexico. Asclepias nummularia is not common in New Mexico, where it has been found in Grant, Hidalgo, and Sierra counties, and is only locally common in Texas in the Davis Mountains (Jeff Davis County), and additionally in Brewster and Presidio counties. Populations from San Luis Potosí and south with narrower leaves have been segregated as A. nummularioides W. D. Stevens; recognition of this taxon requires further evaluation.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
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CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
IL Wildflowers, 
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MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria, 
SW CO Wildflowers, Turner Photog. 
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