DICOTYLEDONOUS PLANTS 177 



without wings, obovate, 2-toothed at summit or notched, with 

 long hairs or without. Pappus none or a pair of bristles. 



E. Califor'nica Nutt. Gray pubescent at first but becoming 

 smoother and greener. Leaves alternate, ovate to lanceolate, 1-2 

 in. long. Involucre covered with white hairs. Rays an inch long, 

 yellow. 



XX. LEPTOS'YNE 



Smooth succulent herbs, with leaves twice or thrice pin- 

 nately parted iuto narrow, linear lobes. Heads on long 

 peduncles, with a double involucre, the outer of 5-8 narrow, 

 leaf-like scales, the inner of 812 thinner and broader erect 

 scales. Rays yellow, conspicuous, oblong, 3-toothed, 10-nerved. 

 Receptacle nearly flat, with thin papery chaff that falls with 

 the fruit. Corollas of the disk flowers with a slender tube 

 having a ring around the summit below the funnel-form 

 border. Akenes flat, more or less margined with a wing. 

 Pappus none, or a minute cup. 



a. L. Douglasli DC. Annual. Stems leafy only at base. Heads 

 on long, naked peduncles. Rings on the corolla tube hairy. Common 

 in southern California. 



b. L. Stiirmani Gray. Stems leafy below. Involucre hairy at 

 base. Ring on the corolla tube smooth. This is the commonest species. 



c. L. marit'ima and L. gigante'a are shrubby, perennial species 

 with thick fleshy stems. The former grows near San Diego on the 

 coast ; and the latter, which has a strong odor of turpentine, near 

 the coast in Ventura and San Luis Obispo Counties, and on the 

 islands off the coast of Santa Barbara. 



XXI. BIDENS, Bur Marigold 



Annual herbs, usually growing near water. Leaves opposite. 

 Involucre double, as in Leptosyne. Receptacle flat or convex, 

 the thin, narrow, chaffy scales falling with the fruit. Akenes 

 with a pappus of 2-4 awns, barbed downwards. The species 

 are somewhat uncertain. 



XXII. MA'DIA, f arweed 



Annuals with glandular, aromatic foliage and flowers that 

 wilt during the heat of the day. Bracts of the involucre in 



