56 The Oh'io Journal of Science [Vol. XVIII, No. 2, 



short peduncled; rays 40-70, linear, white or commonly tinged 

 with purple, bracts of the hemispherical involucre hispid. 

 Pappus double, the inner a series of slender fragile deciduous 

 bristles, often wanting in the disk flowers, the outer a persistent 

 series of short partly united scales. In fields. May to Novem- 

 ber. General. 



4. Erigeron ramosus (Walt.) B. S. P. Daisy Fleabane. 

 A plant resembling Erigeron annus but often lower and the 

 pubescence more appressed. Basal and lower leaves spatulate, 

 usually serrate; stem leaves linear-oblong to linear-lanceolate, 

 mostly entire. Rays white or purplish, sometimes minute 

 or wanting; bracts of the involucre glabrous or nearly so. In 

 fields. May-November. General. 



Leptilon Raf. Horseweed. 



Annual or biennial herbs. Heads small, in a racemose, or 

 paniculate inflorescence. Involucre campanulate, of narrow 

 bracts imbricated in 1-2 series. Ray flowers carpellate, white, 

 shorter than the disk flowers. Disk flowers bisporangiate. 

 Pappus of numerous bristles, in 1 series. 



1. Leptilon canadense (L.) Britt. Common Horseweed. 

 Erect wand-like plants with leafy hispid-pubescent or glabrate 

 stems, 3-10 ft. high, the larger plants much branched. Leaves 

 often pubescent or ciliate, the basal and lower ones spatulate, 

 petioled, incised, dentate or entire, 1-4 in. long, obtuse to acute; 

 stem leaves linear, mostly entire. Heads usually numerous, 

 about \ in. broad; rays numerous, white, shorter than the 

 pappus; involucre campanulate, its bracts linear, acute, glabrate, 

 the outer shorter. In fields and waste places. June-November. 

 General. 



Doellingeria Nees. Flat-top Aster. 



Perennial, branching, leafy herbs. The upper leaves large, 

 mostly entire, acute or acuminate; lower leaves much reduced; 

 basal leaves none. Heads numerous, in a corymbose inflores- 

 cence; involucre campanulate to hemispherical, of thin 

 appressed, often scarious margined bracts imbricated in several 

 series; ray flowers carpellate, white and not very numerous; 

 disk flowers bisporangiate, white to greenish. Pappus double, 

 the outer of short bristles, the inner of long capillary bristles. 



1. Stem leaves lanceolate to ovate; heads mostly numerous. D. umheUata 



1. Stem leaves obovate, heads commonly few. D. infinna. 



