Astragalus miser var. serotinus
Astragalus miser var. praeteritus
Cooper's weedy milkvetch, timber milk-vetch, weedy milk-vetch
Yellowstone milkvetch
strigulose, hairs basifixed.
strigulose, hairs obscurely malpighian, silvery cinereous, ± straight.
10–35 cm.
(1.5–)2.5–20 cm.
4–15(–17.5) cm;
leaflets (9 or)11–19(or 21), blades narrowly elliptic to linear or linear-oblanceolate, (2–)4–30(–40) mm, apex acute or obtuse, surfaces pubescent abaxially, glabrous adaxially.
(1.5–2.5–9.5 cm; leaflets 7–13(–17), blades linear to linear-elliptic or oblong-elliptic, 2–20 mm, apex attenuate to acute, surfaces pubescent;
terminal leaflet confluent with rachis.
loosely (3–)6–16(–24)-flowered;
axis (1.5–)2.5–14 cm in fruit.
loosely (3–)5–12-flowered;
axis (1–)1.5–7.5 cm in fruit.
calyx 3–4.2 mm, tube 2.3–3.1 mm, lobes 0.7–1.3 mm;
corolla whitish or suffused or veined purple, keel pinkish lilac;
banner 7–9.5 mm;
keel 6–7.8(–8.4) mm.
calyx (2.3–)2.8–3.9 mm, tube (1.7–)2.2–2.9 mm, lobes 0.6–1.4 mm;
corolla whitish, ochroleucous, or stramineous, sometimes brownish-veined, keel apex maculate;
banner 6.6–8.6 mm;
keel 6.2–8.3(–8.8) mm.
linear-oblong, 13–18(–21) × 2–2.8(–3.2) mm, glabrous or strigulose.
linear or linear-oblanceoloid, 11–20 × (2–)2.5–3.4 mm, strigulose.
7–10.
7–11.
= 22.
Astragalus miser var. serotinus
Astragalus miser var. praeteritus
Variety serotinus is known from the Columbia Basin in Washington, northward into British Columbia and Rocky Mountains of Alberta, and southward into northwestern Montana.
D. Isely (1998) noted that var. serotinus is contiguous, and blends, with the purple-petaled var. miser. If origin is unknown, var. serotinus is often distinguished from var. hylophilus with difficulty.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Variety praeteritus occurs in southwestern Montana on the upper forks of the Missouri River to adjoining east-central Idaho, to Yellowstone Park and Grand Tetons in northwestern Wyoming.
D. Isely (1998) stated that var. praeteritus represents the more northern aspects of an expanded var. tenuifolius, based on the presence of malpighian pubescence, and he synonymized the two under the latter name. He was unsuccessful in correlating pubescence with geography. It is probable that the two varieties are best combined, but there is a tendency for plants of var. praeteritus to have broader leaflets.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
BC
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
