1907] Hall. Compositae of Southern California. 31 



2 to 4-nerved, linear, acute to attenuate, the inner with very 

 slender tips : aehenes cinereous-hispidulous on the ribs. 



Western borders of the Colorado Desert, in Riverside Co., 

 Hall, nos. 1888, 2142; southern borders of the Mohave Desert, 

 May, 1882, no. 1247, Parish (type of B. Mohavensis Gray), also 

 Jun. 17, 1894 and no. 3711, Parish; Providence Mts., Brandegee; 

 Inyo Co., Purpus; thence to Utah and Arizona. 



B. Mohavensis is described by Gray as having " bracts of the 

 involucre obtuse." Through the kindness of Dr. Robinson I 

 have had the opportunity of examining a head from the type 

 sheet in the Gray Herbarium and although the bracts (especially 

 the outer ones) are somewhat broader and less acute than in 

 typical B. Urn folia, the difference is not sufficiently great to be 

 of specific value. Moreover, specimens collected by Parish (Rose 

 Mine, Jun. 17, 1894; and north slope San Bernardino Mts., no. 

 3711) near the type locality of B. Mohavensis have the slender 

 bracts of B. lini folia, and this character is somewhat variable 

 even in collections from Utah, whence came the original B. 

 linifolia. The pubescence, pappus, and aehenes, likewise fail to 

 yield constant characters for the separation of B. Mohavensis. 



4. B. frutescens Gray, Proc. Am. Acad. xvii. 207 (1882). 

 Coleosanthus frutescens Kuntze, 1. c. 



A rigid shrub with divaricate often spinose branches : herbage 

 cinereous-pubescent: leaves all alternate, linear-spatulate to 

 obovate, obtuse, entire, .5 to 1.5 cm. long : heads scattered, about 

 35-flowered (about 20-flowered, ace. to Gray) : involucre cam- 

 panulate, 9 to 12 mm. high ; bracts 2 to 4-nerved, acute or rather 

 obtuse, the short and oblong outer ones somewhat greenish- 

 tipped: aehenes hispidulous-scabrous : pappus-bristles minutely 

 serrulate. 



Lower Sonoran Zone: San Felipe, western borders of the 

 Colorado Desert, Parish, Purpus, etc.; Mountain Springs, San 

 Diego Co., Vasey, ace. to Gray; Lower California. 



5. B. Nevinii Gray, Proc. Am. Acad. xx. 297 (1885). Coleo- 

 santhus Nevinii Heller, Cat. N. Am. PL ed. 1, 8 (1898). 



Stems slender, long, loosely branched: herbage white-tomen- 

 tose, the tomentum becoming loose and scurfy, especially on the 



