Ragweed Tribe 413 



with an excavated cartilaginously bordered areola about each. 

 (Franseria tenui folia Gray.) 



Rather common about Cahuenga Pass. 



2. Gr. acanthicarpa (Hook.) Britton. Annual, diffuse, hir- 

 sute or hispid; the stems and branches 3-10 dm. long; leaves 

 ovate or roundish in outline, 2.5-7 cm. broad, bipinnatifid ; sterile 

 racemes numerous, short; fruiting involucre 6-8 mm. high, with 

 flat lanceolate-subulate spines. (Franseria acanthicarpa Hook.) 



Not uncommon on the dry plains of the interior valleys. July-September. 



3. G-. bipinnatifida (Nutt.) Kuntze. Perennial, procumbent ; 

 stems 6-10 dm. long, hirsute; leaves ovate in outline, 2.5-5 cm. 

 long, 2-3-pinnately parted, with oblong lobes, canescent with soft 

 tomentum or finely hirsute ; staminate spikes or racemes dense ; 

 fruiting involucre ovate-fusiform, 6-8 'mm. long, armed with 

 rather short and thick flattish spines, their acute tips somewhat 

 incurved. (Franseria bipinnatifida Nutt.) 



Common along the seashore on beach sands and on the sand-dunes. 

 Flowering nearly throughout the year. 



28. XANTHIUM L. COCKLE-BUR. 



Monoecious annual branching coarse rough or spiny 

 herbs, with alternate lobed or dentate leaves, and rather 

 small heads of greenish flowers, the staminate ones capi- 

 tate-clustered at the ends of the branches, the pistillate 

 axillary. Involucre of the staminate heads with short 

 distinct bracts in 1-3 series ; receptacle chaffy ; corolla 

 tubular, 5-toothed ; anthers not coherent, mucronate at 

 apex ; filaments united. Involucre of pistillate heads 

 ovoid or oblong, closed, covered with hooked spines, 1-2- 

 beaked, 2-celled, each cell containing 1 ovoid or oblong 

 achene ; corolla none ; pappus none. 



1. X. spinosum L. Widely branching from the base, about 

 6 dm. high; leaves ovate-lanceolate, more or less lobed or pinna- 

 tifid, glabrate and green above, white-tomentose beneath ; axils 

 each with a short-stalked sponged yellow spine about 2 cm. long; 

 burs about 10 mm. long, armed with short weak prickles. 



Frequent along roadsides and in waste places. August-October. 



