422 COMPOSITAE. 



oblong, compressed, nol ribbed, smooth and glabrous. Pappus of a single 

 series of bristles, plumose or barbellate to the middle, clavellate-dilated at tip, 

 united into a ring at the base and deciduous as a whole. (Kirsion, Greek 

 name of a kind of thistle.) 



A. Naturalized species. 

 Stems conspicuously winged by the decurrent leaves, the wings rigid, spiny and Inter- 

 rupted 1. C. lanceolatum. 



B. Native species. Stems not decurrently winged, or if decurrent, 



the wing not rigid or spiny. 



1. Heads nodding. 



Involucral bracts herbaceous, very broad from the appressed base to the squarrose-spread- 



ing or recurved abruptly acute apex; narrower innocuous inner ones comparatively 



few; heads nodding 2. C. fontinale. 



2. Heads erect, leafy bracted. 



Involucral bracts not appressed- imbricated ; heads clustered or not conspicuously long- 

 peduncled, erect as in all the following. 

 Leaves thin, sinuately lobed, very prickly but the prickles weak; involucre somewhat 



cobwebby; stems succulent; common 3. C. cdulc. 



Leaves thickish, pinnately parted into 3-lobed segments, ending in very stout spines; 

 uppermost leaves lanceolate, as stoutly spinose-tipped as the lower; involucre 



arachnoid-woolly, its bracts cartilaginous at base; rare 4. C. andrewsii. 



Similar to the last, but the involucres glabrous; leafy bracts few, very similar to the 

 proper bracts and pectinate-spinescent; lower San Joaquin 5. C. crassicaule. 



3. Heads erect, naked. 



a. Involucral bracts appressed-imbricate in many ranks. 

 Involucral bracts with the outer successively shorter, the slender short spine at their tip 

 more or less abruptly spreading, the innermost erect, devoid of spine. 

 Bracts linear-lanceolate, entire, with needle-like termination. 



Heads campanulate to ovate, 1 to 1^ in. high; tall glabrate plant of salt marshes 



6. C. hydrophilum. 

 Heads small, cylindric, 1 in. or less high; slender plant, 4 to 7 ft. high, commonly 



white-woolly 7. C. breweri. 



Bracts very broad and comparatively short, entire; heads iy 2 to 2 in. high; plants low, 



commonly l / 2 ft. high 8. C. quercetorum. 



Bracts roundish and dilated at apex, the margin lacerate-f ringed; heads 1 to 1^ in. 



high ; plants 1 to 2 ft. high 9. C. callilepc. 



b. Involucral bracts not appressed-imbricated; heads on long peduncles. 

 Involucre broadly turbinate, its bracts elongated-oblong or linear or subulate, cuspidate or 

 scarious at apex, lacerately fringed or entire, erect or little spreading, not squarrose, 



glabrate or nearly so 10. C. remotifoliitm. 



Involucre campanulate and its base depressed about the summit of the peduncle; outer 

 involucral bracts prickle-tipped, stout and squarrose-spreading. 

 Bracts slender, spreading, straight or incurved, appressed at the very base; corollas 

 cream-color or white, the segments shorter than the throat; Mt. Diablo range and 



southern Sierra Nevada 11. C. calif ornicum. 



Bracts with closely appressed base and long-lanceolate widely spreading portion, this 



straight, or incurved and hook-like; middle and inner Coast Ranges 



12. C. coulteri. 



Bracts straight, densely festooned with cobwebby hairs; sand hills along the coast 



13. C. occidentalc. 



1. C. lanceolatum (L.) Scop. Bull Thistle. Plant spreading, 2 to 3% 

 ft. high; herbage villous and green; leaves lanceolate, deeply pinnatifid into 

 lanceolate lobes, the callous midribs and veins excurrent as rigid spines, the 

 base decurrent on the stem into interrupted prickly wings; upper surface 

 strigose-setulose; heads large, almost 2 in. high, terminating leafy branchlets; 

 bracts of involucre lightly arachnoid-lanceolate, attenuate into slender and rigid 

 prickly pointed spreading tips; flowers rose-purple. 



European Bpecies, Introduced in recenl years in the Bay region: Berkeley; 

 Lower Ban Joaquin, etc. 



2. C. fontinale (Greene) Jepson. Stout, about 2 ft. high, the branches 

 widely spreading; Btems ami upper surface of leaves more or loss glandular- 



