Rydberg: Studies on Rocky Mountain Flora 534 



Leaves over 5 mm. wide. 



Raceme simple ; petals long-clawed and sub- cordate at the base. 



Z. falcatttm. 

 Raceme branched ; petals short-clawed, not sub-cordate at the base. 



Z. paniculatuiii. 

 Petals and sepals clawless ; gland obovate with a poorly defined margin ; fila- 

 ments free. Z,. Nuttallii. 



Zygadenus elegans Pursh, Fl. Am. Sept. i : 241. 18 14 

 The typical Z. clcgans is a western plant, mainly belonging to 

 the Rocky Mountain region, where it grows in meadows up to an 

 altitude of 2500 m. If the eastern plant or Z. glmiais of Nuttall, 

 should be included in this species, is very doubtful. It is always 

 darker green, more glaucous, inflorescence more paniculately 

 branched, the petals and sepals narrower and more greenish. It 

 ranees from New Brunswick to Minnesota and south to Vermont. 

 The range of Z. elegans proper is from Saskatchewan to Alaska, 

 south to Colorado and Nevada. 



Zygadenus Coloradensis sp. nov. 



A rather slender glabrous plant, 2-4 dm. high. Bulb ovoid, 

 about 2 cm. long and i-l5 cm. in diameter: leaves narrow, 

 erect, about 2 dm. long, 3-5 mm. wide : flowers racemose, yel- 

 lowish white-tinged with brownish or purplish : bracts linear- 

 lanceolate, all equaling or exceeding the pedicels : petals and 

 sepals 5-6 mm. long, 3-7-nerved, oblong or narrowly obovate, 

 acute: capsule ovoid, 15-18 mm. long and 7-8 mm. in diameter. 



Z. Coloradensis is closely allied to Z. elegans, differing in the 

 smaller flowers, greener foliage, long and narrow bracts equaling 

 or exceeding the pedicels and a brownish or purplish tint of the 

 inflorescence, bracts and flowers. It grows in the mountains at 

 an altitude of 2500-3500 m. 



Colorado: Idaho Springs, 1895, Rydberg i\.y^€); Leroux 

 Creek, 1892, /. H. Coiven ; La Plata, 1873, Coidter ; Caribou, 

 1 89 1, Dr. E. Penard ; Empire, 1892, H. N. Patterson, 2g8. 



Zygadenus venenosus Wats. Proc. Am. Acad. 14: 279. 1879 



This species is characterized by its narrow leaves, of which the 



upper lack the scarious sheaths, and by the thick, prominent 



* When the petals or sepals are sub- cordate at the base and long- clawed the gland 

 is at the very base but when they are acute at the base the gland is a little higher up 

 on the blade. 



