480 COMPOSITE. 



17. C. cymosus. Stout and rigid, the strongly striate-angled and 

 deciduously floccose-woolly stem 3 — 4 ft. high, simple below, shortly and 

 cymosely branched at summit, with many short-peduncled heads form- 

 ing a somewhat flat- topped general inflorescence: leaves rather small, 

 pinnatifid and spinescent, white-floccose on both faces: heads about 1}4 

 in. high; bracts of the involucre not very numerous, the outer ovate and 

 lanceolate, closely appressed except at the stoutly spinescent tip, 

 flocculent-tomentose, destitute of glutinous spot, the inner with linear- 

 elongated thm tips: corolla dull- white, the segments little shorter than 

 the throat : pappus with dilated and barbellate tips above the plu- 

 mose part. — Dry hills of Alameda and Contra Costa counties. June, 

 July. 



18. C. Breweri, Greene, 1. c. 363; Gray, Proc. Am. Acad. x. 43 (1874), 

 under Cnicus. Permanently and densely white-woolly, 4—10 ft. high: 

 leaves numerous and rather ample, pinnatifid: heads many, panicled, 

 and often rather densely so, at summit of stem; involucre round-ovate, 

 only 1 in. high, arachnoid when young, the outer bracts short and 

 broad, with a glutinous or glandular spot at the tip, the prickle weak: 

 lobes of the purple or whitish corolla shorter than the throat: tips of the 

 anthers almost obtuse.— In the Sierra Nevada at middle elevations; also 

 near the level of the sea in Mendocino and Monterey counties. June — 

 Aug. 



19. C. quercetoriiiii, Greene, 1. c. 362; Gray, Proc. Am. Acad. x. 40 

 (1874), under Cnicus. Perennial by branching horizontal rootstocks: 

 sparingly villous-arachnoid when yonng, soon glabrate: stem stout, 1 ft. 

 high or less, with few rather large heads: leaves mostly petiolate, the 

 larger 1 ft. long, pinnately parted, the oblong divisions often 3— 5-cleft, 

 prickly: involucral bracts coriaceous, closely imbricated in numerous 

 ranks, the outer with short prickles, the inner obscurely scarious at tip: 

 corollas either dull-purple or white: anther-tips narrow, very acute. — 

 Open grassy summits and higher slopes of hills, chiefly, if not exclu- 

 sively, in the region of San Francisco Bay. June, July. 



20. C. LANCEOiiATUs, Liuu. Sp. PI. ii. 821 (1753). More or less 

 villous or hirsute, seldom cottony; 2—4 ft. high, stem and branches in- 

 terruptedly winged by the decurrent leaves, both leaves and wings 

 prickly: heads nearly 2 in. high, arachnoid- woolly at first, the bracts 

 lanceolate, attenuate into slender and rigid prickle-pointed spreading 

 tips: ti. rose-purple. — A most troublesome Old World weed, already 

 abundant on this coast far northward, only lately established in central 

 California. 



