Parry, Amer. Naturalist. 8: 212. 1874. (as Stanley atomentosa).
(caudex simple, covered with persistent petiolar remains); pubescent or glabrous.
erect, unbranched or branched distally, 5-15 dm, (tomentose throughout or glabrate distally).
petiole 0.3-1.2 cm; blade lanceolate to oblanceolate, 6.7-19(-23) cm × 20-50(-60) mm, margins runcinate, (surfaces densely tomentose).
petiolate; (proximalmost similar to basal), blade lanceolate, 2-4 cm × 5-10 mm (smaller distally), margins entire to hastate.
dense, (considerably elongated in fruit).
horizontal to divaricate-ascending, 11-22 mm, (pilose or glabrous).
sepals linear, 10-16 mm, pubescent; petals pale lemon yellow, linear, 12-21 × 1-1.8 mm, claw 8-15 mm, (nearly linear), slightly wider at base, glabrous; filaments 12-22 mm, glabrous; anthers 4-5.5 mm; gynophore 10-20 mm, glabrous.
suberect to ascending, straight, flattened, 4-7 cm × 1.2-2.2 mm; ovules 30-46 per ovary; style 0.02-0.3 mm.
oblong, 1.8-2.6 × 1-1.5 mm.
Flowering Jun-Aug. Rocky limestone hillsides, knolls, steep grassy banks, sagebrush communities, stony clay slopes; 1300-2300 m; Idaho, Wyo.
is known in Wyoming from Big Horn, Hot Springs, and Park counties. R. C. Rollins (1993) recognized two varieties and distinguished them primarily on the basis of having sparsely pilose (var.
) versus glabrous (var.
) distalmost stems. The distinction is artificial and unwarranted.