442 COMPOSITAE. Vor. IL. 
36. LEPTILON Raf, Am. Month. Mag. 2: 268. 1818. 
[Caenotus Raf. Fl. Tell. 2: 50. 1836.] 
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. Besides the following, 2 or 3 others occur in 
the southwestern United States and one is naturalized from Asia on the southern Atlantic and 
Pacific coast. Type species: Leptilon divaricatum (Michx.) Raf. 
1. Leptilon canadénse (L.) Britton. Horse-weed. Canada Fleabane. 
Fig. 4378. 
Erigeron canadensis L. Sp. P1?863. 1753. 
Leptilon canadense Britton, in Britt. & Brown, IIl. 
Fl. 3: 391. 1898. 
Stem hispid-pubescent or glabrate, 3’-10° high, 
the larger plants paniculately much branched. 
Leaves usually pubescent or ciliate, the basal and 
lower spatulate, petioled, incised, dentate or en- 
tire, 1-4’ long, obtuse or acutish, those of the 
stem linear and mainly entire; heads usually very 
numerous; about 2” broad; involucre campanu- 
late, 1-14” high, its bracts linear, acute, gla- 
brate, the outer shorter; rays numerous, white, 
shorter than the pappus and mostly shorter than 
their tubes. 
In fields and waste places, a common weed through- 
out North America except the extreme north. Widely 
distributed as a weed in the Old World, the West 
Indies and South America. Butter-weed. Prideweed. 
Fireweed. Blood-staunch. Cow’s-, mare’s- or colt’s- 
tail. Hogweed. Bitter-weed. June-Nov. 
2. Leptilon divaricatum (Michx.) Raf. Low 
Horse-weed. Purple Horse-weed. Dwarf 
Fleabane. Fig. 4379. 
Erigeron divaricatus Michx. Fl. Bor. Am. 2: 123. 1803. 
Leptilon divaricatum Raf. Am. Month. Mag. 2: 268. 1818. 
Stem diffusely much branched, 3’-12’ high, pubescent 
or hirsute. Leaves all linear or subulate, entire, 4’—12 
long, about 4” wide, the uppermost minute; heads nu- 
merous, about 2” broad; involucre campanulate, 1” 
high, its bracts linear, acute, pubescent, the outer 
shorter; rays purplish, shorter than their tubes. 
In sandy soil, especially along rivers, Indiana to Minne- 
sota, Tennessee, Louisiana, Nebraska and Texas. June—Oct. 
