COMPOSITAE. 251 



Stems many-leaved; involucre imbricated. H. canadense. 



Stems few-leaved; involucre a series of equal bracts and a 

 few short outer ones. 

 Flowers white; involucre nearly glabrous. H. albiflorum. 



Flowers yellow; involucre hairy or glandular. 



Heads small, black-hairy. H. gracile. 



Heads larger; hairs not black. H. scoukri. 



Hieracium canadense Michx. Somewhat scabrous throughout; stems 

 stout, 30-120 cm. high; leaves numerous, lanceolate, entire or incisely serrate, 

 sessile and somewhat clasping at base, gradually smaller upwards, 1-10 cm. 

 long, none clustered at base; heads corymbed, rarely solitary, on stout pe- 

 duncles; involucre hemispheric, puberulent or glabrous, sometimes glandular, 

 1-2 cm. broad, the bracts in 2-3 series, the uppermost loose; akenes columnar; 

 pappus brownish. Low ground, rare. 



Hieracium canadense columbianum (Rydb.) Piper. {H. columhianum 

 Rydb.) Lower part of stem pilose, otherwise as in the species. Spokane 

 County. 



Hieracium albiflorum Hook. Stems slender, erect, 50-80 cm. high, villous 

 below; leaves oblong or oblong-spatulate, thin, entire or faintly toothed, the 

 lower tapering into broad petioles, the upper mostly sessile, all beset with 

 sparse villous white hairs, especially the lowest; heads lS-30-flowered; in- 

 volucre narrow, glabrous or with a few hairs, the bracts linear-lanceolate, pale; 

 akenes strongly striate. In dry open woods. 



Hieracium gracile Hook. Tufted; stems usually several, 15-30 cm. high; 

 leaves mostly basal, oblong-spatulate, entire or nearly so, broadly petiolate, 

 3-8 cm. long, glabrous or merely puberulent; heads several, racemose or corym- 

 bose; involucre 8 mm. high, blackish with both hirsute and glandular hairs; 

 akenes cylindric; pappus sordid or fuscous. An alpine species occurring on 

 the higher peaks of the Blue Mountains. 



Hieracium scouleri Hook. Erect, 30-60 cm. high, densely beset throughout 

 with long soft white hairs with swollen bases; basal leaves lanceolate or ob- 

 lanceolate, entire, acute or obtuse, 10-20 cm. long, tapering into margined 

 petioles; cauline similar, sessile, 5-12 cm. long; inflorescence corymbose or 

 paniculate, glandular; involucre 1 cm. high, very glandular and long-villous; 

 flowers yellow; akenes columnar; pappus fuscous. Common on hillsides. 

 Very variable in the amount and length of the pubescence. 



374. CENTAUREA. 



Herbs; heads many-flowered; flowers all with tubular and 

 deeply 5-cleft corollas, some of the marginal ones commonly 

 sterile, often much larger and conspicuous, the others perfect 

 and fertile; involucre globular, the scales tipped or margined 

 with spines or scarious appendages; receptacle very bristly; 

 pappus of numerous rigid or sometimes chaffy naked bristles; 

 akenes mostly compressed, attached by one margin just above 

 the base. 



Annual, white woolly; leaves linear or lanceolate, entire. C. cyanus. 



Biennial, green; leaves oblong to lanceolate, some dentate. C. consimilis. 



Centaurea cyanus L. Bachelor's Button. Stems erect, slender, usually 

 branched, 30-90 cm. high; heads solitary on slender branches; involucre 



