Duration: Perennial Nativity: Native Lifeform: Forb/Herb General: Herbaceous perennials, showy, acaulescent or nearly so, herbage green to white silky-hairy (sericeous), with at least some of the hairs dolabriform; (shaped like an axe-head under magnification). Leaves: Pinnate, all basal, leaflets 7-17, linear to oblong, 5-40 mm long, silvery-sericeous on both sides. Flowers: Purple, corollas 12-25 mm long, the keel abruptly narrowed into a prominent beak, calyx tube 5-9 mm long, the teeth about half as long or less, flowers borne in spike-like racemes, the heads many-flowered, loose, elongate to subcapitate, (the inflorescences sometimes quite tall, appearing like stems). Fruits: Pods oblong to cylindric, gradually narrowed to a beak, not greatly inflated, 1-2 celled, indehiscent. Ecology: Found on sandy soils in open places and pine forests, from 5,000-8,000 ft (1524-2438 m); flowering June-September. Distribution: Canada south to Texas, New Mexico, and Arizona. Notes: At first glance, this plant looks very similar to an Astragalus, look to the dense, soft, white, long-silky hairs to help identify this species; even the caudex is covered with the dense fuzz. Oxytropis has a prominent beaked keel, lacks stems (acaulesecnt), and has erect or ascending scapes (flower stalk). The caudex can become well-developed and stacked on older plants, another good indicator for this genus. The other Oxytropis in Arizona according to Kearney and Peebles; O. oreophila, has ovate, inflated pods and is silvery-sericeous. Ethnobotany: The plant was used for constipation. People used the plant and seeds to make a mush or was parched and used for food. The plant taken or consumed in quantities was considered poisonous to livestock and horses, conversely, the plant was also used as horse feed. The plant was also offered to the bighorn at the Night Chant. Synonyms: Oxytropis lambertii var. bigelovii, many others, see Tropicos Editor: LCrumbacher 2011 Etymology: Oxytropis comes from oxys, "sharp," and tropis, "keel," in reference to the beaked flower petals, while the meaning of lambertii is unknown.
Lfls 9-19, linear to narrowly oblong, 1-2.5 cm, thinly strigose- canescent with malpighian hairs; spikes 4-10 cm; cal densely villous; fls purple (white), 1.5-2 cm; fr cylindric, very firm, sometimes soon glabrous, the body 8-15 mm, the beak 3-7 mm; 2n=48. Dry prairies and plains; Minn. and s. Man. to nw. Mo., Okla., and Tex., w. to Mont., Utah, and Ariz. May, June. Ours is var. lambertii.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.