Nelson : New Plants from Wyoming 33 



leaflets : cyme many-flowered, loose and open : hypanthium softly 

 pubescent, in fruit I cm. in diameter: bractlets linear-lanceolate, 

 a little shorter than the broadly lanceolate sepals : corolla large : 

 petals broadly obcordate, 8-10 mm. long, distinctly surpassing the 

 bracts and sepals. 



This member of the Graciles section is to be compared with P. 

 etomentosa Ryd. It is separated from that by its slender habit, 

 differences in leaflets, in bracts and pubescence, and by larger 

 flowers with petals decidedly surpassing the sepals. In some re- 

 spects it suggests jP. dissecta glaucophylla, but is a much larger and 

 more nearly erect plant. Collections of it are Green Top, June 

 28, 1897^ no. 3223*2, and Pole Creek, July 22, 1897, no. 3420, 

 both localities in the Laramie Hills. 



y 



Erigeron luteus 



Densely tufted on a multicipital caudex : leaves closely crowded 

 on the crowns, all narrowly linear with slightly tapering, petiole- 

 like base, sub-cinereous with a minute pubescence, 3-5 cm. long : 

 stems monocephalous, simple, one only from each crown, scape- 

 like but bearing 2 or more short leaves below, these obscured by 

 the numerous, fascicled crown leaves, the peduncular portion 

 usually with one small bract, from barely exceeding the leaves to 

 about twice as long : heads 6-8 mm. high, the involucral bracts 

 linear, acutish, somewhat unequal and in two rows, rather shorter 

 than the disk : rays 30-40, a pure yellow, rather broad and short, 

 the ligule only 3-4 mm. long : pappus in two series, the outer of 

 very short, inconspicuous bristles ; the inner bristles rather sparse 

 and coarse, nearly as long as the tube of the disk corollas : akenes 

 minutely pubescent. 



A distinctlv vellow Et 



Two 



collections of this show it constantly and strikingly so. It is true 

 that Dr. Gray, in Syn. Fl. 213, admits some pure yellow forms 

 into his E. peuccphyllus but those are admitted into that species as 

 exceptions. The localities and colors as there given would lead 

 one to believe that the original of that species had pale blue rays 

 and came from British Columbia. This in connection with the 

 fact that E. peucephylliis is a larger plant, with coarser and much 

 taller and more leafy stems, with sometimes 2-3 heads, coarser 

 pubescence, larger and fewer rays, etc., leads me to think that 

 these yellow Rocky Mountain forms may best stand as a species. 

 The characterization of E. peucephyllus as densely caespitose on 



