Astragalus miser var. praeteritus
Astragalus miser var. serotinus
Yellowstone milkvetch
Cooper's weedy milkvetch, timber milk-vetch, weedy milk-vetch
strigulose, hairs obscurely malpighian, silvery cinereous, ± straight.
strigulose, hairs basifixed.
(1.5–)2.5–20 cm.
10–35 cm.
(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.
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.
loosely (3–)5–12-flowered;
axis (1–)1.5–7.5 cm in fruit.
loosely (3–)6–16(–24)-flowered;
axis (1.5–)2.5–14 cm in fruit.
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.
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.
linear or linear-oblanceoloid, 11–20 × (2–)2.5–3.4 mm, strigulose.
linear-oblong, 13–18(–21) × 2–2.8(–3.2) mm, glabrous or strigulose.
7–11.
7–10.
= 22.
Astragalus miser var. praeteritus
Astragalus miser var. serotinus
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.)
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.)
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
BC
WA
Flora NW
