1907] Hall.Compositac of Southern California. 281 



1. C. virens L., Sp. PL ed. 2, 1134 (1763). SMOOTH HAWKS- 

 BEARD. 



Annual or biennial, 3 to 7 dm. high: stem slender, simple 

 below, paniculate above : herbage green and glabrous, or some- 

 what hirsute below: radical leaves numerous, oblanceolate. 

 toothed to pinnatifid, narrowed at base into a petiole; cauline 

 leaves lanceolate, with sessile subsagittate base ; uppermost leaves 

 commonly linear or subulate and entire : heads many : involucre 

 7 to 9 mm. high, somewhat calyculate ; its bracts linear, acumin- 

 ate, often pubescent : achenes linear-oblong, narrowed equally to 

 each end, 10-ribbed. 



On Big Rock Creek, desert slopes of the San Gabriel Mts.. 

 Jul. 6, 1896, Davidson. Introduced from Europe. 



2. C. biennis L., Sp. PL 807 (1753). ROUGH HAWKSBEARD. 



Biennial, branched above, 5 to 12 dm. high: herbage pubes- 

 cent, often hirsutely so, especially above : lower leaves oblong or 

 spatulate, runeinate-pinnatifid or sometimes merely dentate, nar- 

 rowed at base into a petiole ; upper cauline leaves sessile by a 

 sagittate-dentate base: involucre 9 to 12 mm. high: achenes ob- 

 long, somewhat narrowed above, 13-ribbed. 



Streets of Pasadena, ace. to McClatchie. Introduced from 

 Europe. 



3. C. acuminata Nutt., Trans. Am. Philos. Soc. ser. 2, vii. 437 

 (1841). 



Perennial, slender, 3 to 8 or 9 dm. high, cymosely branched 

 above: herbage cinereously puberulent but the inflorescence 

 nearly glabrous : lower leaves 15 to 25 cm. long, broadly lanceo- 

 late in outline, pinnatifid with narrow spreading or retrorse lobes, 

 attenuate below into a petiole and above into a tail-like prolong- 

 ation 8 cm. or less long : involucre narrow, 10 to 12 mm. high ; 

 minute outer bracts canescent ; inner bracts 5 to 8, bright green, 

 glabrate: flowers 5 to 10: achenes fusiform, somewhat narrowed 

 at summit. 



On dry slopes in open forests of the Transition Zone: San 

 Bernardino Mts., at Bear Valley, Parish, no. 1460, and Upper 

 Santa Ana Canon, Hall, no. 7538 ; Frazier and Alamo Mts., Ven- 

 tura Co., Hall, nos. 6596, 6702; Mt. Pinos, in Kern Co., Hall 



