524 COMPOSITES. 



5. E. idoneum. Branching from the hase, 12 to 16 or 30 in. high, 

 the herbage at first woolly, later deciduous and floccose; leaves 

 mostly basal, linear-spatulate or obovate in outline, laciniate or pin- 

 natifid, green above, the tomentum mostly persistent on the under 

 surface; heads solitary on long naked peduncles or the heads 

 somewhat corymbosely clustered and the peduncles shorter; involucre 

 hemispherical, 3 or 4 lines high, its bracts broadly lanceolate, appear- 

 ing as if united or eonnivent by reason of the dense felt-like tomen- 

 tum; rays 9 to 12; ligules elliptic, 5 to 6 lines long, sharply notched 

 at summit, with a small tooth in the notch; pappus-palese about 9, 

 very short. 



Yaca Mountains (where it is undoubtedly annual); Napa Co. hills. 

 ilay.-June. 



6. E. lanatum (Pursh.) var. grandiflorum Gray. Whole plant 

 white-woolly, the tomentum tardily deciduous, 1 or 2 ft. high; leaves 

 ovate or obovate in outline, pinnately divided into narrow toothed or 

 pinnatifid segments; peduncles long and naked; involucres broadly 

 hemispherical (8 lines broad); rays about 11, J in. long and over one- 

 half as wide. 



Hillsides, Peaceful Glen Valley, Solano Co.; Sierra Foothills. 

 May-.Tune. 



41. RIGIOPAPPUS Gray. 



Slender annual with alternate very narrowly linear entire leaves. 

 Heads small, solitary on the simple stems or on the branches, which 

 are often proliferous. Receptacle flat, naked. Bracts subulate, 

 similar to the upper leaves. Flowers yellow. Eay-corollas not ex- 

 ceeding the disk, the ligule not longer than the tube. Disk-corollas 

 small, with 3 to 5 short erect teeth. Pappus in disk and ray of 3 to 

 5 subulate awns. Achenes linear. (Greek rigios, stiff, and pappos, 

 pappus.) 



1. R. leptocladus Gray. Three or 4 to 10 in. high, the herbage 

 short-hairy or nearly glabrous; branches filiform; heads 3 lines high; 

 achenes hispidulous. 



Wooded hills: North Coast Ranges; Tehama Co.; Sierra Foothills. 

 June. 



42. CH/ENACTIS DC. 



Ours annuals with alternate pinnately parted or dissected leaves 

 and yellow flowers. Heads peduncled, solitary or cymosely arranged. 

 Bracts of the campanulate involucre herbaceous, linear, equal, in one 

 series. Receptacle flat, naked. CoroUas'with short tube and long 

 throat, or the marginal corollas in some species with the limb pal- 

 mately enlarged, forming a. kind of ray. Pappus of hyaline palese, 

 the palea3 in the outer flowers commonly shorter and fewer. (Greek 

 chaino, to gape, and aktis, ray, in reference to the marginal flowers of 

 one section of the genus.) 



Stems short, leafy mostly at base, the peduncles long and scape-like; palese 

 commonly 4, equal or nearly so . . . . 1. C. lanosa. 



