Asclepias meadii
Asclepias welshii
Mead's milkweed
Welsh's milkweed
1 (rarely 2), erect, unbranched, 20–80 cm, glabrous, glaucous, rhizomatous.
1–20, erect to ascending, unbranched, 35–100 cm, densely tomentose to glabrate, not glaucous, rhizomatous.
opposite, sessile, with 1 stipular colleter on each side of petiole;
blade ovate to lanceolate, 4.5–10 × 1–5 cm, chartaceous, base rounded to obtuse, margins entire, apex acute, venation brochidodromous, surfaces glabrous, glaucous, margins inconspicuously ciliate, laminar colleters absent.
subopposite to opposite (alternate), sessile or petiolate, stipular colleters absent;
petiole 0–8 mm, tomentose to glabrate;
blade oblong or obovate to oval or ovate, 4.5–14.5 × 2–8 cm, subsucculent, base rounded to cordate, margins entire, apex rounded or truncate to emarginate or acute, mucronate, venation brochidodromous, secondary veins orthogonal, surfaces tomentose to glabrate, margins eciliate, 0–10 laminar colleters.
terminal, rarely branched, pedunculate, 7–19-flowered;
peduncle (0–)3–10 cm, sparsely pilosulous to glabrate, glaucous, with 1 caducous bract at the base of each pedicel.
extra-axillary from upper nodes, pedunculate, 22–80-flowered;
peduncle 2.5–6 cm, densely tomentose, with 1 caducous bract at the base of each pedicel.
11–20 mm, pilosulous.
10–15 mm, densely pilose to tomentose.
pendent;
calyx lobes narrowly lanceolate, 4–5 mm, apex acute, pilosulous;
corolla green to greenish cream, sometimes tinged red, lobes reflexed with spreading tips, oval, 7–9 mm, apex acute, glabrous;
gynostegial column 1.5–1.8 mm, fused anthers green, truncately obconic, 2–2.5 mm, wings right-triangular, closed, apical appendages ovate;
corona segments green to yellowish green or greenish cream, sessile, conduplicate, dorsally rounded, 4–5.5 mm, greatly exceeding style apex, base saccate, apex obtuse, emarginate, slightly flared, glabrous, internal appendage falcate, exserted, sharply inflexed towards style apex, glabrous;
style apex shallowly depressed, green.
erect to pendent;
calyx lobes linear, 5–6 mm, apex acute, densely pilose to tomentose;
corolla ochroleucous or tan to red-violet, lobes reflexed with spreading tips, oval to oblong, 5.5–6.5 mm, apex acute, densely tomentose abaxially, glabrous adaxially;
gynostegial column 1–1.5 mm;
fused anthers green to tan, obconic, 1.5 mm, wings triangular, widest at middle, closed, apical appendages ovate;
corona segments cream to ochroleucous, sometimes green at base, shiny, stipitate, tubular, dorsally flattened, 2.5–3.5 mm, exceeding style apex, apex truncate, glabrous, internal appendage falcate with acicular tip, exserted, sharply inflexed over style apex, glabrous;
style apex shallowly depressed, green.
ovate, 6–7 × 4–5 mm, winged, faces coarsely papillose;
coma 3–4.5 cm.
oval, 18–20 × 9–10 mm, margin winged, faces minutely rugulose;
coma 4–4.5 cm.
erect on upcurved pedicels, narrowly fusiform, 7–14 × 0.9–1.6 cm, apex long-acuminate, smooth to minutely rugulose, puberulent with curved trichomes.
pendulous on spreading pedicels, ellipsoid, 5–7 × 1.7–3 cm, apex acuminate, softly muricate, densely to thinly tomentose.
Asclepias meadii
Asclepias welshii
With respect to historical range reduction and potential threats, Asclepias meadii is the most endangered North American milkweed species and is considered to be of conservation concern in each of the states in which it occurs. Nearly all of the viable populations are now restricted to Missouri and eastern Kansas; many of these are found in hay meadows, in which fruit maturation does not occur. Asclepias meadii is endemic to the highly-impacted tallgrass prairie ecoregion and is thought to be rare as a result of habitat loss. Consequently, concern for the continued existence of this species can be considered emblematic of concern for the tallgrass prairie as a whole. Active recovery efforts have achieved limited success, with newly established populations experiencing high mortality and slow growth of transplants. It has been re-introduced to Indiana and Wisconsin, but long-term survival of these populations is uncertain. The sessile, glaucous leaves and pendent umbels on a long peduncle suggest a diminutive version of A. elata; however, these species do not appear to be closely related (Fishbein et al. 2011). The terminal inflorescence of pendent umbels is unique among tallgrass prairie milkweeds.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
With respect to the number of populations, Asclepias welshii is the most endangered Asclepias in the flora area and is federally listed as threatened in the United States. Most of the populations are remote and relatively secure; however, the most accessible population in a Utah park has been subject to the impacts of off-road vehicle recreation. Leaves and stems of A. welshii emerge densely tomentose, but the lower portions of the plants become sand blasted and smooth as the season progresses. The species is strongly rhizomatous, as befits its shifting substrate. Seedlings and sprouts from rhizomes often bear narrowly linear leaves that differ so strongly from the foliage of more robust stems that they are not easily attributed to this species. Similar heterophylly is found in A. arenaria, A. erosa, and other milkweeds of sandy substrates.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
IL Wildflowers
KS Wildflowers
MO Plants
WildflowerSearch
iNaturalist
USDA Plants Database
