Cymopterus nivalis S. watson: Cespitose perennial from a stout taproot and freely branching caudex that is clothed by the petioles and leaf bases from previous years; scapes or peduncles several or rather numerous, slender, loosely ascending, mostly 3-15 cm long; leaves all clustered at the base, evidently to obscurely granular-scaborous or wholly glabrous, the blade 1-5 cm long and 0.3-1.5 cm wide, subbipinnatifid to subtripinnatifid with 4-8 pairs of primary pinnae, the lower pinnae, commonly more or less remote, the upper more crowded, the ultimate segments crowded and small, only 1-3 mm long, the petiole shorter than to about as long as the blade; inflorescence small and compact, up to about 1 cm wide at anthesis, only a little wider (up to about 2 cm) in fruit, the 3-8 rays becoming 2-4 mm long, or the umbellets only 2, one sessile, the other on a ray about 1 mm long, the fruiting pedicels short, mostly 1-2 mm long; involucre wanting, the involucel dimidiate, or well developed, scarious-margined or partly anthocyanic, distinct or basally connate bractlets 2-5 mm long; calyx teeth short, broad, and soft, less than 0.5 mm long; petals white; anthers purple; carpophore well developed, bifid, persisting on the pedicel after the mericaraps have fallen; fruit 3-6 mm long, dorsally compressed, broadly winged, the oil-tubes 5 or 6 in the intervals, about 10 on the commissure.
Rocky Ridges, pockets of soil among rocks, and dry alpine meadows, or seldom in organic soil under conifers, at high elevations in the mountains. (1800) 2700-3300 m often above timberline; Western Montana, Western Wyoming, in most of the mountains of central and eastern Nevada, (East Humboldt, Hot Creek, Monitor, Ruby, Snake, and Toquima ranges), and on Steens Mt. in se. Oregon; also at 1550 m in nc. Lake County, Oregon. June-July.