298 COM POSITS PYRROCOMA 



erous, pistillate, sometimes infertile or inconspicuous: disk-flow- 

 ers cylindrical, slightly dilated upward, with short erect teeth. 

 Style-branches of the ray-flowers often unequal, or one of them 

 abortive, glabrous: those of the disk-flowers subulate-linear, 

 elongated, the hispid appendages much longer than the stigrnatic 

 portion. Achenes linear, elongated, somewhat 3-angled and 

 striate glabrous or rarely hairy. Pappus reddish-brown or ful- 

 vous, of copious and uniform slender rigid bristles 



* Heads large and discoid the sterile rays being hardly apparent 

 or very small for the size of the head : achenes glabrous and smooth, 

 slender but flattish, 4-costate or nerved often finely striate 



P. carthamoides. Hook- Fl. i, ^06. t. 107. Sten.s rigid several from 

 the same root, tt-12 inches high, leafy, -cabro puberuler<t when young, be- 

 coming smooth, bearing a solitary terminal large head and sometimes one 

 or t\v<> in axils: leaves from sputulate to oblong or lanceolate: coriaceous, 

 sparingly spinulose-serrulate the lowest 3-4 inches long, taperinginto slen- 

 der petioles: involucre hemispherical, d-l" lines high, often leafy- 

 subtended at base, its proper bracts coriaceous rigid, from oblong to 

 br >ad v lanceolate or the innermost linear, niore or loss scarious-margin- 

 ed. most of them tipped with an abrupt mucro or cusp, the outer com- 

 monly loose and becoming leaf-like either entire or spinulo?e-denticulate : 

 rays almost always present and rather numerous, but their ligules incon- 

 spicuous, being short involute and concealed in the pappus On plains and 

 rocky hillsides ; British Columbia to () egon and Idaho. 



P. radiata N'utt Trans. \m. i'hil. Soc n. ser, vii 333. Whole plant 

 glabrous,: stem stout, 12-18 inches high: leaves thick, the radical and lower 

 caulino obovate-oblong.ihe lowest 3-H inches long by 2 inches broad, petio- 

 led the upper cauline ovate-lanceolate or oblong: heads usually several 

 and somewhat corymbose, an inch high and broad, bracts of the invo- 

 lucre numerous, broad or broadish : raws very narrow, exserted but incon- 

 spicuous : arhenes 4 lines long, about the length of the rigid expanding 

 pappus, the bristles of which are barbellate-scabrous I 'ry plains near 

 Walla Walla. Washington 



ar. 



1*. nsiekii Greene Eryth. ii, o9 Aplop'tppu* earth 'moides V 

 irkii Gray Stems 6-18 inches high ascending few-leaved : leaves mostly 

 spatulate- lanceolate; heads comparatively smali and few-flowered, termi- 

 nal and subterminal : bracts of the involucre rather few, lanceolate, most- 

 ly acute or acuminate. Union County. Oregon Cusick. 



* * Heads middle-sized to small, evidently radiats: the exserted 

 rays often infertile but styliferous 



P. racemosa ' . & G. Fl ii, LM4, Stems glabrous, 12-18 inches high, 

 bearing 3-7 racemose heads at the summit : leaves glabrous, lanceolate, 

 slightly spinulose-serrate, the upper acute, oblong-lanceolate, partly clasp- 

 ing, the lower tapering to the base, somewhat petioled : heads hemispher- 

 ical, less than an inch in diameter: involucre imbricated, in 3 series its 

 ovate oblong scales pubescent ; ray-flowers conspicuous and fertile; disk 

 corollas shorter than the pappus: achenes sparsely hirsute. Plains of 

 the < olumbia. 



* * Heads obovoid, sessile and often clustered : involucre as long 

 as the disk, the scales linear-oblong, with short distinct herbaceous 

 tips imbricated in several series: achenes glabrous. 



P. paniculata T & (I 1 c. Glabrous. > terns a foot high, branched at 

 the summit: leaves oblong-lanceolate, mucronate, obscurely and remotely 



