156 University of California Publications in Botany. [ VOL - 3 



are deciduous. Eeceptacle small and flat, bearing in our species 

 about 5 perfect disk-flowers, these surrounded by a single row 

 of distinct chaffy bracts. Rays cuneate, palmately 3-cleft. Ray- 

 achenes obcompressed, obovate-oblong, smooth, nearly straight, 

 pointless : disk-achenes slender, sterile. Pappus none. Bracts 

 and achenes all deciduous at maturity. 



1. L. ramosissima Nutt., Trans. Am. Philos. Soc. ser. 2, vii. 

 391 (1841). 



Usually simple, strict throughout or paniculately very much 

 branched above, 2 to 8 dm. high: leaves (especially the upper) 

 silky-hirsute with soft hairs, the short ones subtending the heads 

 densely villous-ciliate ; lower leaves oblanceolate or linear-lanceo- 

 late, often narrowed at base to a slender petiole, 3 to 6 cm. long, 

 early deciduous: heads almost sessile, crowded on the leafy 

 branchlets or the lower somewhat scattered ; the involucre 6 mm. 

 high : rays barely exserted, pale yellow, changing through salmon- 

 color to saffron: fertile achenes carinately 1-nerved down the 

 inner face. 



Frequent in open places of the Upper Sonoran Zone from the 

 Cuyamaca Mts. (Palmer, no. 181) and San Bernardino to Oregon 

 and from the coast barely to the Desert Area (Mohave River. 

 Parish. ) 



57. LAYIA H. & A. 



Vernal annuals with mainly alternate leaves and medium- 

 sized heads on evident peduncles. Bracts of the involucre flat- 

 tened on the back below, with abruptly dilated thin margins 

 infolded so as to enclose the ray-achene, the tip flat. Ray-flowers 

 8 to 20 ; ligules yellow, white, yellow tipped with white, or roseate. 

 Disk-corollas yellow, their lobes hirsute or villous. Receptacle 

 broad and flat, with a row of thin bracts between ray and disk- 

 flowers and sometimes additional ones among the flowers. Ray- 

 achenes obcompressed, commonly glabrous, destitute of pappus, 

 fertile. Disk-achenes usually pubescent, mostly sterile, in ours 

 bearing a pappus of 5 to 20 bristles or awns (these rarely wanting 

 in the last species). 



