COMPOSITAE (COMPOSITE FAMILY) 501 



2. Oonopsis argillacea A. Nels. Bull. Torr. Bot. Club 26: 481. 1899. 

 Tufted, caespitose, the crowns more or less covered with the bases of dead 

 leaves; stems numerous, 3-8 cm. long, terminating in a leafy corymbose in- 

 florescence of few heads, sparsely lanate-pubescent as are also the leaves: 

 leaves entire, narrowly to broadly linear, pungently acute, 4-8 cm. long, often 

 overtopping the heads: involucre tomentose, about 1 cm. high; the bracts 

 oblong-ovate, acuminate, not conspicuously green-tipped: rays showy, about 

 10, the disk-flowers twice as many: achene softly pubescent, oblong, 3-4 mm. 

 long. On barren clayey slopes and flats; interior Wyoming. 



3. Oonopsis Engelmannii (Gray) Greene, 1. c. Stems 1-2 dm. high, in 

 tufts from a subterranean branching caudex, simple, very leafy up to the 

 cymose-glomerate heads: leaves all narrowly linear, 3-5 cm. long, only 2-3 

 mm. wide, rigid: bracts of the involucre regularly imbricated and appressed, 

 outer similar but short, all abruptly mucronate or short-cuspidate, slightly 

 greenish below the tip. Plains of Colorado at Hugo. 



4. Oonopsis Wardii (Gray) Greene, 1. c. 46. Dwarf; fascicled stems 10-15 

 cm. high: leaves 3-6 cm. long, linear-lanceolate, destitute of lateral nerves: 

 heads 10 mm. or less long, 2 or 3 in a terminal glomerule: achenes double the 

 length of the scanty pappus. Wyoming, " probably in the southwestern part." 



5. Oonopsis condensata A. Nels. 1. c. 25: 376. 1898. Stems spreading, 

 mostly simple below, freely and fasciculately branched upward, 1.5-2.5 dm, 

 long, very leafy, especially above: leaves glabrous, broadly linear to narrowly 

 oblanceolate, 1-nerved or often 3-nerved at base, acute, 6-12 cm. long: in- 

 florescence of the tufted plant as a whole dense, from rounded to almost 

 flat-topped; inflorescence of the branchlets a close glomerule of about 3 heads, 

 often overtopped by the upper leaves: heads rayless, 15-25-flowered, 10-15 mm. 

 high; involucral bracts lanceolate-acuminate, nearly equaling the flowers: 

 achenes striate, flattened-clavate, glabrous, when mature 6 mm. long; pappus 

 scanty, about equaling the achene. In gravelly clay soils in a few restricted 

 localities; Laramie Plains, Wyoming. 



6. Oonopsis monocephala A. Nels. Bot. Gaz. 31: 399. 1891. Caudex 

 woody, the branches slender; stems 1 or more from each branch of the caudex, 

 erect or ascending, 1-2 dm. high, simple, uniformly leafy from base to summit, 

 monocephalous: leaves glabrous as are also the stehis, linear-oblong, sessile, 

 acute, quite uniform in size and shape, 5-8 cm. long, about 1 cm. broad, the 

 uppermost involucrating the large head: involucre hemispherical, about 

 15 mm. high; the bracts oblong, rather abruptly short, acuminate-cuspidate, 

 glabrous but for some ciliate pubescence on the margins: heads rayless; disk- 

 flowers very numerous: pappus nearly as long as the corolla-tube, the bristles 

 widely spreading at /naturity; achene oblong, about 3 mm. long, sparsely 

 and obscurely glandular. Known only from the type locality, Berwind, 

 Colorado. 



7. Oonopsis foliosa (Gray) Greene, 1. c. Glabrous; stems erect or ascend- 

 ing from a woody base, 1.5-3 dm. high, corymbosely branched above, leafy: 

 leaves oblong or linear-oblong, sessile, partly clasping at the base, acute with 

 a mucronate tip, entire or occasionally somewhat denticulate; lower ones 

 5-7 cm. long, tapering to the base; upper ones clasping by a broad base: 

 heads terminating the leafy branches, globose, 2-3 cm. in diameter; bracts 

 in 3-4 series, lance-ovate, with acuminate, spiny tips, somewhat villous- 

 pubescent, with narrow, scarious margins: rays 12-15 mm. long, lance-ovate, 

 yellow: pappus a little shorter than the corolla and rather longer than the 

 very smooth achene. Aplopappus Fremontii. On clayey plains and hills; 

 upper Arkansas in Colorado. 



14. MACRONEMA Nutt. 



Low and viscidly pubescent, much branched shrubby plants, the fastigiate 

 leafy branches terminated by solitary or fastigiately clustered rather large 

 heads, with entire sessile leaves and yellow flowers. Heads many-flowered, 

 discoid or radiate; disk-flowers tubular, perfect. Bracts of the involucre 



