1907] Hall.Compositae of Southern California. 209 



81. POROPHYLLUM Vaill. 



Slender perennial herbs of arid districts; very glabrous but 

 the involucres dotted with oil-glands. Leaves narrowly linear, 

 entire. Heads solitary, narrow, discoid. Involucre of about 5 

 broadly oblong equal bracts, with no calyculate outer ones. Style- 

 appendages subulate. Achenes (in our species) attenuate at 

 apex, rusty-pubescent. Pappus of numerous capillary bristles. 



1. P. gracile Benth., Bot. Sulph. 29 (1844). 



Plant 3 to 9 dm. high, with numerous very slender branches : 

 leaves few, filiform-linear, 1 to 5 cm. long, entire : involucre 10 

 to 15 mm. high, naked at base, often purplish-tinged; its bracts 

 oblong, obtuse, bordered with a hyaline margin : corollas dull 

 white arid purple. 



Common on arid plains and hillsides from near the coast of 

 San Diego Co. across the Colorado Desert to Arizona and Texas ; 

 south into Mexico. Also collected in the Cismontane Area (that 

 is, west of the mountains) near Riverside; and on the Mohave 

 Desert at Needles. Herbage strongly and disagreeably scented. 



82. PECTIS L. 



Low branching herbs. Leaves opposite, connate, usually bear- 

 ing glands containing an essential oil, hence often aromatic. 

 Heads medium-sized or small, mostly radiate, solitary or sub- 

 corymbose. Involucre cylindrical or campanulate, of a single 

 series of equal bracts which are inclined to embrace the ray- 

 achenes. Style hispidulous, the short branches obtuse and with- 

 out appendages. Achenes fertile in both disk and ray, terete. 



1. P. papposa Harv. & Gray, PL Fendl. 62 (1849) ; Fernald, 

 Proc. Am. Acad. xxxiii. 85 (1897). CHINCH- WEED. 



Plant low, divergently much branched, the branches com- 

 monly short, but vigorous specimens often forming mats 4 dm. 

 in diameter: leaves opposite, narrowly linear, 1 to 5 cm. long, 

 entire or with a few sharp lobes, bearing 2 to 5 pairs of basal 

 setae: heads 6 mm. high, on peduncles 6 to 20 mm. long: rays 4 

 to 8 mm. long, yellow : achenes rusty-pubescent : ray-pappus a 

 mere crown, rarely 1 or 2 awns; disk-pappus of 12 to 20 bristles, 

 or sometimes reduced to a crown. 



