Rydberg: Studies on Rocky Mountain Flora 536 



A rather stout light greeti plant, ^-6 dm. high. Bulb elon- 

 gated ovoid, about 3 cm. long and 1. 5 cm. in diameter: leaves 

 scabrous on the midrib and margins, 2 dm. or more long, 5-9 

 mm. wide, keeled and sometimes conduplicate ; all with conspicu- 

 ous scarious sheaths at the base : raceme rather long : flowers 

 light yellow ; petal and sepals 6-8 mm. long, obtuse ; the for- 

 mer broadly ovate, and acute or rounded at the base and short- 

 clawed ; the latter oblong subcordate at the base and with a claw 

 I mm. long : glands as in the preceding. 



Like the preceding but taller and stouter, in habit resembling 

 mostly Z. panicidatiis, except that the inflorescence is seldom 

 branched. It is easily distinguished from that species by the ob- 

 tuse petals and sepals and by the distinct claws and the subcordate 

 bases of the petals. It grows on dry hillsides up to an altitude of 

 2000 m. in Montana, Idaho, Wyoming and Utah. 



Idaho: Nez Perces Co., 1892,/. H. Sandbcrg, 10364 (type); 

 Peter Creek, 1892, Sandberg, MacDoiigal & Heller, 114; Lewis- 

 ton, 1896, A. A. & E. Gertrude Heller, 30^3. 



Utah: Farmington, 1881, M. E.Jones, 2ogi. 



Wyoming: Laramie Hills, 1894, Aven Nelson, 234. 



Montana: Deer Lodge, 1895, F.N. Notestein ; Bridger Moun- 

 tains, 1897, Rydberg & Bessey,384g. 



Zygadenus acutus sp. nov. 



A very slender light green plant, 3-5 dm. high. Bulb rounded 

 ovate, 1.5-2 cm. long, 1-1.5 cm. in diameter: leaves narrowly 

 linear, scabrous on the margin, about 2 dm. long and 4-5 mm. 

 wide, keeled and often conduplicate : flowers pale yellow : petals 

 and sepals 4-5 mm. long ; both acute at the apex and at the base, 

 very short-clawed : glands obovate or cuneate ; upper margin 

 toothed, thin and not well defined. 



In habit closely resembling Z. venenosns, but easily distin- 

 guished by the acute, short-clawed petals and sepals, which are 

 both cuneate at the base. The only specimens seen are the fol- 

 lowing : 



South Dakota: Box Elder Creek, Black Hills, 1887, W. S. 



Riisby. 



Zygadenus falcatus sp. nov. 

 Z.Niittallii Porter & Coult. Syn. Fl. Colo. 133. In part. 

 1874. Not A. Gray. 



