546 



COMPOSITE. 



pubescent and somewhat strigose; leaves once or the lower twice 

 pinnatifid; fruit an obovoid turgid bur, mostly solitary in the axils, 

 bearing 4 protuberances or sometimes unarmed. 



Uncultivated lands in the Sacramento Valley and southward; 

 common about San Francisco Bay. Sept. -Oct. 



65. FRANSERIA Cav. 

 Branching herbs, ours perennial, sometimes woody at the base. 

 Leaves chiefly alternate. Habit, flowers and inflorescence as in 

 Ambrosia. Involucre of the pistillate heads closed, 1 to 4-celled, 1 

 to 4-beaked or pointed, armed with several rows of prickles and in 

 fruit becoming a bur. (Named for Ant. Franser, Spanish botanist.) 



Leaves twice or thrice pinnatifid or pinnately parted . . .1. F.bipinnatiflda. 

 Leaves (at least the upper) undivided and merely serrate . 2. F. C'hamissoni*. 



1. F. bipinnatifida Nutt. Herbaceous; stems procumbent, 2 or 

 3 ft. long, somewhat hirsute; leaves twice or thrice pinnately parted 

 into oblong lobes, canescent or almost silky; spikes dense; bur nar- 

 rowly ovate, armed with thick somewhat flattened spines, some of 

 which are curved at the tip. 



Common on sandy seabeaches along the coast, and also at Alameda 

 and West Berkeley. Aug. -Oct. 



2. F. Chamissonis Less. Habit of the preceding; leaves nar- 

 rowly ovate or obovate, with cuneate base, serrate, or the lower 

 laciniate or incised; bur thicker, sparsely hirsute, the spines broader 

 and channeled. 



Seabeaches along the coast; less common. 



66. XANTHIUM L. 



Coarse (by same called vile) annual weeds with widely branching 

 and very stout stems. Leaves alternate, toothed or lobed, petioled. 

 Heads unisexual, composed of greenish flowers. Staminate heads 

 subglobose, in a terminal cluster: — involucre of several distinct nar- 

 row bracts in a single row; receptacle cylindrical; flowers many, 

 separated by the bracts of the receptacle; corolla tubular. Pistillate 

 heads axillary, below the staminate: — involucre closed, forming in 

 fruit an ovoid or oblong indurated bur covered all over with hooked 

 prickles, 1 or 2-beaked, 2-celled, each cell containing 1 flower; 

 corolla none; pappus none; style 2-cleft, its branches exserted through 

 the beaks. (Greek xanthion, yellow, from its yielding .a hair-dye of 

 that color. ) 



Leaves deltoid-ovate; stems not spiny 1. A". Canadense. 



Leaves lanceolate; stems bearing spines by the sides of the leaves 



2. X. spinosum. 



1. X. Canadense Mill. Cockle Bur. Stems about 2 ft. high, 

 not prickly; leaves deltoid-ovate or somewhat cordate, irregularly 

 serrate, or somewhat incised, often distinctly 3-lobed, rough, hispidu- 

 lous and green both sides, 3 to 4 in. long, on petioles nearly as long; 

 bur £ to 1 in. long, thick, pubescent or glandular between and on the 



