404 ASTERACEAE. 



2. C. calif ornicum Gray. Rather slender, 6-12 dm. high, canes- 

 cently woolly; leaves sinuate-pinnatifid, moderately prickly; heads 

 solitary on long peduncles, about 4 cm. high; involucres somewhat 

 woolly; the lower bracts coriaceous-acerose, spreading and incurved, 

 the others straight, all subulate-spinescent at the tip; flowers lilac- 

 purplish or rose color; lobes shorter than the throat. 



Occasional in open places in the Santa Monica, San Gabriel and 

 Santa Ana Mountains. May-July. 



3. C. occidentale (Nutt.) Jepson. Stout, 6-9 dm. high; leaves 

 deeply pinnatifid, glabrate above, canescently tomentose beneath; 

 heads solitary on stout peduncles; involucre subglobose; bracts 

 straight, subulate-lanceolate, with short spines, densely covered 

 with cobwebby hairs; flowers deep red-purple; lobes longer than 

 the throat. 



Common on sandy soil, especially toward the coast. May-July. 



66. CYNARA L. Artichoke. 



Stout perennial prickly herbs, with pinnatifid sessile 

 leaves, their lobes spinescently tipped, and large heads of 

 purple tubular flowers. Involucral bracts well-imbri- 

 cated, coriaceous, spinescent. Receptacle flesh}^, fimbril- 

 late. Achenes obovate, compressed and somewhat 4- 

 angled. Pappus of many series of plumose bristles. 



1. C. scolymus L. Stout and low, with very ample hoary- 

 tomentose bipinnatifid leaves; involucral bracts ovate, obtuse or 

 emarginate. 



An occasional escape from gardens. June-July. 



67. SILYBUM Vaill. 



Annual or biennial herbs with ample prickly clasping 

 leaves. Heads very large, solitary at the ends of the 

 branches. Involucral bracts broad appressed, tipped 

 by broadly lanceolate spreading spines. Corolla with 

 filiform tube conspicuously dilated below the narrow 

 lobes. Pappus bristles in several series, barbellate. 

 Filaments united below into a tube. 



1. S. marianum (L.) Gaertn. (Milk Thistle.) Stems branch- 

 ing, stout, 1-2 m. high; leaves glabrous, shining above and con- 

 spicuously spotted with white blotches along the veins, sinuate- 

 pinnatifid and undulate, the upper merely spinose-toothed ; heads 

 3-5 cm. broad; corolla purple. 



Introduced from southern Europe, and becoming rather common 

 as a wayside weed. 



68. CENTAUREA L. 



Annual or perennial herbs, with alternate entire den- 

 tate or pinnatifid leaves, and large or middle-sized heads 



