394 



CARDUACEAE. 



plants three or four inches high, taken to the New York Botanical Garden in the 

 late autumn of 1912, grew rapidly and flowered profusely in April, 1913. The 

 species was named in honor of Hon. J. K. Darrell, a prominent member of an old 

 Bermuda family, Mr. Hemsley remarks on the similarity of this plant to Conyza 

 rivularis Gardn., of Brazil. 



8. LEFTIIiON Raf. 



Annual or biennial herbs/ with, small racemose thyrsoid or panicled heads 



of white flowers, the rays small, usually shorter than the diameter of the disk 



or none. Involucre mostly campanulate, its narrow bracts in 2 or 3 series. 



Receptacle naked. Ray-flow^ers pistillate ; disk-flowers perfect, their corollas 



usually 4-lobed or 4-toothed, the anthers obtuse at the base; style-branches 



somewhat flattened. Achenes flattened. Pappus of numerous simple bristles. 



[Greek, referring to the small heads.] About 20 species, of America and Asia. 



Type species: Erigeron divaricatum Michx. 



Inner involucre-bracts densely pubescent. 

 Inner involucre-bracts glabrous or nearly so. 



Pubescent ; involucre-bracts green. 



Glabrate ; bracts purple-tipped. 



1. L. linifolium. 



2. L. canadense. 



3. L. pusillum. 



1. Leptilon linifolium (Willd.) J. K. 

 Small. Hairy Horse-weed. (Fig. 431.) 

 Stems 6'-3° tall, hirsute, racemosely or panic- 

 ulately branched above. Leaves narrowly 

 spatulate to linear, i'-4:' long, the lower 

 ones incised or laciniate, slender-petioled, 

 the upper entire or sparingly toothed; in- 

 volucres V'-l^" high, the bracts linear to 

 linear-subulate, densely pubescent. \_Erig- 

 eron linifolium Willd.; E. tonariensis of 

 Reade, of Lefroy and of H. B. Small; 

 Conyza annbigua of Millspaugh.] 



Common in waste and cultivated grounds. 

 Naturalized. Native of tropical regions. Flow- 

 ers from spring to autumn. Perhaps not dis- 

 tinct from Erigeron honariensis L. 



2. Leptilon canadense (L.) Brit- 

 ton. HORSEWEED. FlEABANE. (Fig. 



432.) Stems hirsute, 1°-Q° tall, simple 

 to the paniculate inflorescence; leaves 

 linear or nearly so, or the lower spatu- 

 late, coarsely few-toothed, ciliate; heads 

 numerous; involucres about 1*" high; 

 bracts appressed, linear-subulate to 

 linear, green, the outer ones often pu- 

 bescent; corollas of the disk-flowers 

 usually 4-lobed. [Erigeron canddense L.] 



Common in waste and cultivated 

 grounds. Naturalized. Native of temperate 

 North America. Flowers nearly through- 

 out the year. 



