ASTERACEAE. 371 



Widely distributed over western North America; found on the 

 edge of our limits in Swartout Canyon, San Gabriel Mountains, 

 according to Hall. Common in the San Bernardino Mountains. 



18. LEPTILON Raf. 



Annual or biennial herbs with small racemose or 

 panicled heads of white flowers. Involucre mostly cam- 

 panulate, its narrow bracts in 2 or 3 series. Rays small, 

 usually shorter than the diameter of the disk, pistillate, 

 or none. Disk-flowers perfect, usually 4-toothed or 

 4-lobed. Style-branches short. Achenes flattened. 

 Pappus-bristles in 1 series. 



1. L. canadense (L.) Britton. Stem hispid-pubescent or gla- 

 brate, 2 m. high or less, paniculate, much branched; leaves usually 

 pubescent or ciliate, the lower spatulate, dentate or entire, 5-10 

 cm, long, the upper linear and mainly entire; heads very numerous, 

 about 4 mm. broad; involucre 2-3 mm. high; its bracts linear, 

 acute, glabrate, the outer shorter; rays numerous, white, shorter 

 than the pappus and mostly shorter than their tubes. {Erigeron 

 canadense L.) 



A common weed in waste places and cultivated fields. 



2. L. linifolium (Willd.) Small. Annual or biennial; stems 

 erect, 2-7 dm. high; herbage hispid and scabrous; leaves narrowly 

 spatulate to linear, entire or the lower somewhat toothed; heads in a 

 loose panicle, 4-5 mm. high; involucral bracts linear-subulate, 

 pubescent; ray-flowers minute, white. {Erigeron linifolus Willd.) 



Introduced from the tropics, first collected within the State at 

 San Diego by Miss Stokes in 1895. Now a fairly common wayside 

 weed about Alhambra, Pasadena and San Bernardino. 



19. CONYZA L. 



Ours a viscid pubescent branching annual, with alter- 

 nate leaves, and small many-flowered heads in a crowded 

 thyrsoid leafy panicle. Involucre campanulate, its 

 bracts narrow, appendiculate, in 2-3 series. Pistillate 

 flowers much more numerous than the hermaphrodite, 

 their filiform or slender corollas shorter than the disk 

 and style, truncate or 2-4-toothed. Achenes small, 

 compressed. Pappus a single series of soft capillary 

 bristles, sometimes with an outer series of shorter ones. 



1. C. coulteri Gray. Stems simple below, branching above, 

 about 1 m. high or less, viscid-pubescent or hirsute, with many- 

 jointed hairs; stem-leaves linear-oblong, the lower spatulate-oblong 

 and with partly clasping base, dentate to laciniate-pinnatifid, 2.5-5 

 cm. long; involucre 2-4 mm. high, hirsute with soft spreading hairs; 

 flowers whitish; corolla-tube of pistillate flowers truncate, half the 



