200 Flora of the Palouse Region 



tips scarious or prickly: receptacle thickly clothed with soft bristles 

 or hairs: pappus of numerous bristles united into a ring at the 

 base, plumose, deciduous: akenes oblong, flattish, not ribbed. 



Bracts of the involucre not prickly-pointed. 



Heads very large, sessile. C. fouosum. 



Heads small, peduncled. C. arvense. 

 Bracts of the involucre prickly-pointed. 



Leaves white-tonientose on both sides. C. undulaTum. 

 Leaves green above. 



Flowers whitish: involucre glandular. C. BREWERi. 



Flowers rose-red: involucre very woolly. C. Edule. 



Flowers rose-red: involucre slightly woolly. C. lanceo^atum. 



C. foliosum DC. Stems stout, erect, simple, about i m. high, very leafy, 

 villous and somewhat woolly: leaves lanceolate or linear-lanceolate, pin- 

 nately-lobed, green and villous above, permanentfy white-woolly beneath, 

 10-50 cm. long, only the lowest petioled; prickles numerous, weak and slen- 

 der: heads large, few, in a dense terminal cluster, surrounded at base by the 

 upper leaves which are usually reddish: involucral-bracts loosely imbricated, 

 thin, flat, the outer acuminate, sometimes with a weak prickly point, the 

 inner with scarious dilated somewhat fringed tips: flowers pink, the corolla- 

 lobes as long as or longer than the throat. North hillsides, common. A 

 peculiar plant, apparently a hybrid between this species and C. breweri, 

 sometimes occurs in its company. 



C. arvense Scop. Perennial, with slender creeping rootstocks: whole 

 plant green, thinly tomentose when young, becoming glabrous, much 

 branched, 1-2 m. high: leaves numerous, oblong-lanceolate, pinnately-lobed, 

 sessile and somewhat clasping at base, 10-20 cm. long; prickles numerous, 

 rather weak: heads small, corymbed, dioecious; stamiuate heads globose, 

 the flowers much exserted; pistillate-heads oblong-campanulate, the flowers 

 scarcelv projecting: bracts of the involucres well imbricated, somewhat ciliate, 

 the short ovate outer ones spine-tipped, the inner ones lanceolate, soft- 

 tipped: flowers pink-purple. Sparingly introduced. 



C. undulatum Spreng. Stout, erect, .5-2 m.high, the whole plant except 

 the heads persistently white-tomentose, or the leaves sometimes glabrate 

 above: leaves lanceolate, pinnately-lobed or parted, 5-15 cm. long; prickles 

 few or numerous, rather stout: heads large, on stout peduncles: involucre 

 well imbricated, the bracts thick, with a glandular spot near the tip; all 

 tipped with spreading prickly points: corollas rose-red or whitish, the lobes 

 about as long as the throat: pappus bristles a little thickened at the apex. 

 Along Snake River, common. 



C. breweri Piper, n. comb. (Cnicus breweri Gray .) Stem erect, loosely 

 branched above, 30-90 cm. high, tomentose when young, becoming glabrous: 

 leaves lanceolate, pinnatifid into rather few lobes, early becoming green and 

 glabrous above, persistently white-woolly beneath, 5-15 cm. long; prickles 

 few: heads large, on nearly naked long peduncles: involucre hemispheric; 

 the bracts firm, closely imbricated in several successively shorter ranks; all 

 prickly pointed and bearing an oblong or linear glandular spot near the tip: 

 flowers yellowish-white: corolla-lobes shorter than the throat. Common 

 at Pullman. 



C. edule Nutt. Stems usually tall and nearly simple, 1-2 m. high, 

 thinly pubescent: leaves numerous, lanceolate, pinnately-lobed, pubescent 



