Musineon tenuifolium Nutt. ex Torr. & A. Gray

Tauschia tenuifolia (S. Wats.) Math. & Const. Bull Torrey Club 68: 122. 1941.
Eulophus tenuifolius S. Wats. Proc. Am. Acad. 23: 276. 1888.
Velaea tenuifolia Drude in E. & P. Nat. PH. 3 8 : 169. 1898.
Museniopsis tenuifolia Coult. & Rose, Contx. U. S. Nat. Herb. 3: 302. 1895.
Slender, short-caulescent, erect from a stout taproot, the base of the stem densely fibrous, 3-4 dm. high, glabrous throughout; leaves oblong to oval in general outline, 8-12 cm. long, 4-7 cm. broad, ternately or ternate-pinnately decompound, the ultimate divisions filiform, entire, callous-tipped, 4-10 mm. long; petioles slender, 6-12 cm. long; peduncles slender, 15-25 cm. long; involucre wanting, or of a single foliaceous bract; involucel of several obovate, palmately divided bractlets, exceeding the flowers but a little shorter than the fruit; fertile rays 3-6, slender, 15-30 mm. long; pedicels stout, 2-3 mm. long; calyx-teeth minute; flowers unknown; styles short, spreading; carpophore 2-cleft about one-half of its length, the halves divergent for their apical sixth and then incurved, forming an "eye"; fruit ovoid, tapering slightly at the apex, 4-6 mm. long, 3-4 mm. broad, the ribs low and filiform, much narrower than the intervals; oil-tubes very small and numerous all around the seed; seed crescent-shaped in cross section, the face deeply concave.
Type locality: "In canons of the Sierra Madre." Chihuahua, Pringle 1518. Distribution: Known only from the type locality.

Musineon tenuifolium Nutt.; T. & Cx. Fl. N. Am. 1: 642. 1840.*
Adorium tenuifolium Kuntze, Rev. Gen. 1: 264. 1891. Daucophyllum tenuifolium Rydb. Bull. Torrey Club 40: 69. 1913.
Plants acaulescent, erect, subcespitose, 6-30 cm. high; leaves narrowly oblong in general outline, excluding the petioles 1.5-10 cm. long, 5-25 mm. broad, 1-3-pinnate, the ultimate divisions distinct, linear, acute, 2-30 mm. long, 0.5-1 mm. broad; petioles 1-12 cm. long; peduncles exceeding the leaves, hirtellous at the base of the umbel; involucre wanting, or of 1 or 2 inconspicuous and short to prominent and linear-lanceolate bracts, shorter than or equaling the rays; involucel of several inconspicuous, linear, acute, green bractlets, 1-2 mm. long, exceeding the white or yellow flowers; rays 8-30, subequal, 2-20 mm. long, frequently scabrous; pedicels 1-2 mm. long; fruit ovoid to narrowly oblong, slightly constricted at the apex, 2-5 mm. long, 1-2 mm. broad, granular-scabrous, the oil-tubes mostly 3 in the intervals, 2-4 on the commissure; seedface plane.
Type locality: "Rocky Mountains," probably on the upper Platte River in Wyoming, Nullall. Distribution: Western South Dakota and Nebraska to adjacent Wyoming and Colorado