404 Astereae 



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

 pus-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 numer- 

 ous, 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. 



18. 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, com-, 

 pressed. Pappus a single series of soft capillary bristles, 

 sometimes with an outer series of shorter ones. 



1. C. Coulter! Gray. Stems simple below r , 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-pinnat- 

 ifid, 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 length of the style; hermaphrodite flowers 

 only 5-7; achenes nearly glabrous ; pappus bristles several, sca- 

 brous. 



Occasional in subsaline places. July-September. 



19. BACCHARIS L. 



Dioecious perennial herbs or shrubs, with alternate 

 leaves and small paniculate or corymbose heads of tubu- 

 lar flowers. Involucre of scale-like imbricated bracts. 

 Receptacle flat, naked. Corolla of the pistillate flowers 



