CARDUACEAE. 443 



9. LEPTILON Raf. Am. Month. Mag. 2: 268. 1818. 



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-flowers pistillate; disk-flowers perfect, their corollas 

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

 somewhat flattened, their appendages short. Achenes flattened. Pappus of 

 numerous simple fragile bristles in 1 series. [Greek, referring to - the small 

 heads.] About 20 species, natives of America and Asia. Type species: 

 Erigeron divaricatum Michx. 



Bracts of the involucre very pubescent ; plant hirsute. 1. L. linifolium. 



Plant glabrous or nearly so throughout. 2. L. pusillum. 



1. Leptilon linifolium (Willd.) Small, Fl. SE. U. S. 1231, 1340. 1903. 



Erigeron linifolius Willd. Sp. PI. 3: 1955. 1804. 



Hirsute; stem slender, branched or simple, 7 dm. high or less. Leaves 

 linear or linear-spatulate, 1.5-10 cm. long, the upper entire, sessile, the lower 

 mostly incised-serrate, and petioled; heads paniculate or subracemose, several 

 or numerous; involucre about 5 mm. high, its bracts linear, acuminate, pilose; 

 achenes glabrous; pappus tawny, about 3 times as long as the achene. 



Waste grounds, New Providence at Nassau : Bermuda ; southeastern United 

 States; Cuba; Old World tropics and subtropics. HAIRY HORSEWEED. 



2. Leptilon pusillum (Nutt.) Britton, Torreya 14: 198. 1914. 



Erigeron pusillus Nutt. Gen. 2: 148. 1818. 



Stem glabrate, 7-30 dm. high, the larger plants paniculately much 

 branched. Leaves usually ciliate, the basal and lower spatulate, petioled, 

 mostly entire, 2-10 cm. long, obtuse or acutish, those of the stem linear and 

 mainly entire; heads few or numerous, about 4 mm. broad; involucre, 2-3 mm. 

 high, its bracts linear, acute, glabrate, often purplish-tipped; rays numerous, 

 white, shorter than the pappus and mostly shorter than their tubes. 



Pine-lands, cultivated grounds, sandy soil and scrub-lands, Great Bahama, 

 Ahaco and Andros to Watling's Island, North Caicos and Inagua : Bermuda : conti- 

 nental eastern North America ; West Indies. Formerly included in Erigeron cana- 

 densis L., and thus recorded by previous authors. SMOOTH HORSE WEED. 



10. ESCHENBACHIA Moench, Meth. 573. 1794. 



Herbs, with alternate leaves, and mostly corymbose or panicled heads of 

 tubular flowers. Involucre campanulate, several-many-flowered, its narrow 

 bracts imbricated in 2-several .series, the outermost usually much smaller than 

 the others. Receptacle convex or flat, mostly naked. Marginal flowers pistil- 

 late with narrow or filiform, 2-3-toothed corollas; disk-flowers tubular, perfect, 

 5-toothed. Anthers obtuse at the base. Achenes flattened, their sides nerve- 

 less or 1-nerved. Pappus of 1 or 2 series of bristles. [Commemorates J. F. 

 Eschenbach, German botanist.] Perhaps 50 species, of tropical and warm- 

 temperate regions. Type species: Erigeron aegyptiacum L. 



