Shrubs or herbs, the following species glabrous, mostly tufted, with woody roots, the stems leafy to the top. Leaves entire, linear to lanceolate. Heads cymose at the end of the stem or branches. Involucre campanulate to ovoid, its bracts flat, imbricated in several series, herbaceous, cuspidate, appressed and erect, or the outer spreading. Disk-flowers with a nearly cylindric 5-toothed corolla. Stamens and style included or scarcely exserted. Ray-flowers present or wanting, pistillate. Style-appendages ovate to subulate. Achenes glabrous, or somewhat pubescent. Pappus-bristles coarse, rigid. [Greek, resembling an egg, referring to the ovoid involucre.]

Four known species, natives of central North America. Type species: Oonopsis multicaulis (Nutt.) Greene.

1. Oonopsis Engelmanni (A. Gray) Greene. Engelmann's Oonopsis

Fig. 4206

Bigelovia Engelmanni A. Gray, Proc. Am. Acad. 11: 75. 1876.

Oonopsis Engelmanni Greene, Pittonia 3: 45. 1896.

Perennial by a deep woody root, glabrous throughout; stems stiff, about 8' high, densely leafy. Leaves narrowly linear, sessile, 9"-2' long, less than 1" wide, brittle when dry; heads clustered, or sometimes solitary at the ends of the branches, wide or less, sessile among the upper leaves; involucre oblong-campanulate, its bracts in about 4 series, oblong to spatulate, short-acuminate or mucronate, appressed; ray-flowers none; disk-flowers about as long as the rather rigid capillary pappus-bristles; achenes linear-oblong, narrowed at the base, many-striate.

Western Kansas, Nebraska and Colorado. Sept-Oct.

1 Oonopsis Engelmanni A Gray Greene Engelmann s Oo 877