504 COMPOSITiE. 



Flowers yellow. Eeceptacle with linear bristle-like palese. Outer 

 bracts of the involucre terminating in foliaceous appendages like the 

 stem-leaves; inner bracts more rigid, appressed, ending in a spines- 

 cent tip. Achenes obpyi'amidal, with a crenulate margin at the 

 truncate summit. Pappus-palese of 2 kinds, the outer unequal, 

 ciliate, in several series, the inner in one series and much shorter; or 

 pappus quite wanting in the outer row of achenes. 



1. C. lanatum DC. The outer and inner involucral bracts differ 

 v€ry much. 



Native of the Mediterranean Kegion: spontaneous at San Pran- 

 cisco. 



20. CYNARA Vaill. 



Stout perennial herb with ample pinnatifid or bipinnatifid leaves 

 with spine-tipped segments. Flowers blue. Heads very large, soli- 

 tary on the ends of the branches. Bracts of the involucre broadly 

 ovate, obtuse or emarginate, coriaceous. Eeceptacle fleshy, flmbril- 

 late. Pappus of many series of plumose bristles. Achenes obovate, 

 somewhat 4-angled. (From the G-reek kuon, a dog, the spines of the 

 involucre being likened to dog's teeth. ) 



1. C. Scolymus L. Aktichoke. One to 2J ft. high; herbage 

 more or less tomentose. 



Garden-plant, found by waysides at Napa and Alameda and in old 

 fields near Benicia. 



21. CIRSIUM Scop. Thistli:. 

 Stout mostly biennial herbs. Leaves alternate, prickly or spiny, 

 commonly toothed or pinnatifid. Heads with numerous crimson, 

 white or yellowish flowers, perfect and all alike. Corolla tubular, its 

 segments linear-flliform. Involucre spherical to campanulate, ovoid 

 or cylindrical, its bracts imbricated in many ranks, at least the outer 

 tipped with » spine or prickle, rarely innocuous. Receptacle thickly 

 clothed with soft bristles or hairs. Achenes obovate or oblong, com- 

 pressed, not ribbed, smooth and glabrous. Pappus of a single seriesof 

 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.) 



Stems conspicuously winged by the decurrent leaves, the wings rigid, spiny 

 and interrupted; naturalized species 1. C. lanceolatum. 



Stems not decurrently winged, or if decurrent, the wing not rigid or .spiny; 

 native species (except no. 2?). 



A. Involucral bracts herbaceous, very broad from the appressed base to 

 the squarrose-spreading or recurved abruptly acute apex; narrower 

 innocuous inner ones comparatively few; heads nodding 



2. C. foniinale. 



B. Involucral bracts not appressed-imbricated; heads leafy-oracted, clus- 



tered or not conspicuously long-peduucled, erect as in all the follow- 

 ing. 

 Leaves thin, sinuately lobed, very prickly but the prickles weak; invo- 

 lucre somewhat cobwebby; stems succulent; common ... 



S. C. edulc. 



