2 ( .>8 COMPOSITE PVKROCOMA 



erous, pistillate, sometimes infertile or inconspieuous : 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 stigmatic 

 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. ciirthanioides. Hook- Fl. i, :'>06. t. 107. Stems rigid several from 

 the same rout, H-12 inches high, leafy, -cabro puberule^t when young, be- 

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

 or two in axils: leaves from spatulate to oblong or lanceolate: coriaceous, 

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

 der petioles: involucre hemispherical, d-h 1 lines high, often leafy- 

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

 br >aly lanceolate or the innermost linear, more 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 spinulofe-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 O egon and Idaho. 



P. radiata Noitt Trans. \m. I*hil. Soc n. ser, vii 333. Whole plant 

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

 cauline obovate-oblong.ihe lowest 3-H inches Ions* 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 : rays very narrow, exserted but incon- 

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

 pappus, the bristles of wdiich are barbellate-scabrous I rv plains near 

 Walla Walla, Washington 



P. ■ nsickii Greene Eryth. ii, n9 Aplop'tppus earth >moides Var. Gus- 

 ickii < rr'iy Stems 5-18 inches high ascending few-leaved : leaves mostly 

 spatulate-lanceoiate : heads comparatively small and few-flowered, termi- 

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

 ly acute or acuminate. Union County. Oregon CuHck. 



* * Meads middle-sized to small, evidently radiate: the exserted 

 rays often infertile but styliferous 



P. racemosa 'I . & G. Fl ii, 244, 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 

 corolla^ 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. 



1'. paniculata T & G. 1 c. Glabrous, stems a foot high, branched at 

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



