ASTERACEAE. 375 



involucre and of the receptacle deciduous with the 

 mature fruit, those of the fertile flowers involute or sac- 

 cate-conduplicate, embracing the obovate or oblong ob- 

 compressed achene; those of the sterile flowers plane 

 or concave. Pappus wanting in the fertile flowers, com- 

 posed of a few caducous bristles in the sterile ones. 



1. S. gnaphalioides Nutt. Stems 5-10 cm. long; leaves linear 

 or the upper oblong, obtuse; fruiting bract hyaline, broadly ovate, 

 woolly on the back. 



Occasional in open ground, on wooded slopes, and in the chaparral 

 belt. April-June. 



24. PSILOCARPHUS Nutt. 



Small, usually depressed and much branched floccose 

 annuals, with opposite leaves and globose heads which 

 are sessile in the axils or at the forks. Fruiting bracts 

 numerous, crowded on the globular or oval receptacle, 

 cucullate-saccate, semiobovate or semiobcordate, round- 

 ed at the tip, somewhat membranaceous, apex introrse, 

 the ovate or oblong hyaline appendage inflexed or erect. 

 Achene loose within the bract, oblong or narrow, straight, 

 slightly compressed. 



1. P. globiferus Nutt. Branched from the base and spreading 

 or prostrate; leaves linear or narrowly spatulate, the uppermost 

 little surpassing the very woolly heads; achenes obovate-oblong, 

 about 1 mm. long. 



Frequent on the plains and hills, especially in exsiccated places. 

 April-May. 



2. P. tenellus Nutt. Simple or much branched and forming 

 mats; herbage with appressed wool; heads numerous, 2-4 mm. in 

 diameter; floral leaves often 2 cm. long, linear-spatulate, mucronate. 



Glendale, Braunton; Santa Catalina Island, Blanche Trask; first 

 collected at Santa Barbara by Nuttall. This species is distinguished 

 from P. globiferus by the short closely appressed wool instead of 

 very loose almost arachnoid wool, and by the more numerous and 

 smaller heads. 



25. FILAGO L. 



Erect slender fioccose-woolly annuals with alternate 

 entire leaves and small discoid heads in capitate lateral 

 and terminal clusters. Bracts of the involucre few and 

 scarious. Receptacle convex or subconic, chaffy, each 

 chaff-scale subtending an achene. Outer flowers of the 

 heads in several series, pistillate, their corollas filiform, 

 minutely 2-4-dentate. Central flowers few, perfect, but 

 mainly sterile, their corollas tubular, 4-5-toothed. 

 Achenes terete or slightly compressed. 



