188 University of California Publications in Botany. [VOL. 3 



1. R. leptocladus Gray, Proc. Am. Acad. vi. 548 (1865). 



Slender, erect, a few cm. to 3 dm. high: herbage short-hairy 

 or nearly glabrous : involucre 6 mm. high ; bracts becoming con- 

 cave around the ray-achenes : achenes hispidulous. 



Upper Sonoran Zone: San Francisquito Canon, Los Angeles 

 Co., Hall & Chandler, no. 7395 ; Santa Inez Mts., Santa Barbara 

 Co., Brandegee; Cuyama, San Luis Obispo Co., May 7, 1896, Miss 

 Eastwood; Fort Tejon and San Emigdio Potreros, Kern Co.. 

 Hall, nos. 6269, 6432 ; Tehachapi, Kern Co., Hasse & Davidson. 

 no. 1675; north to Washington and east to Nevada (Miss Stokes). 



73. CHAENACTIS DC. 



Annuals and low perennials with alternate pinnately parted 

 or dissected or sometimes entire leaves and yellow or white 

 flowers. Heads peduncled, solitary or cyj^osely arranged. In- 

 volucre campanulate; its bracts herbaceous, linear to lanceolate, 

 commonly equal, in one series. Receptacle flat, naked. Corollas 

 with short tube and long throat, or the marginal corollas in some 

 species with the limb palmately enlarged, forming a kind of ray. 

 Pappus of hyaline paleae, the paleae in the outer flowers com- 

 monly shorter and fewer, early deciduous or wanting in the last 

 species. 



A. Pappus-paleae persistent, entire or merely erose. 



Flowers yellow: annual 1. C. glabriuscula. 



Flowers white or purplish tinged. 

 Annuals. 



Stamens exserted from the corolla-tube. 



Pappus of disk-flowers of 4 equal paleae, or these sometimes 

 unequal (paleae rarely 5 to 6 in C. Fremonti). 



Involucral bracts setaceously acuminate 2. C. carphoclinia. 



Involucral bracts obtuse or merely acute. 



Leaves pinnatifid, with short thick lobes 3. C. stevioides. 



Leaves entire or with a few elongated slender lobes 



4. C. Fremonti. 



Pappus of 4 equal paleae about as long as corolla and 2 to 4 



very small outer ones 5. C. Xantiana. 



Stamens included 6. C. macrantha. 



Perennials: pappus of 8 to 15 equal paleae. 



Leaf -lobes crowded, crispate 7. C. santolinoides. 



Leaf-lobes fewer, not crispate, mostly entire 8. C. Parishii. 



