(i54) 



longer callus-hairs and the deep purple color of the panicle 

 readily distinguish it. 



Calamagrostis Canadensis acuminata Vasey. Dawson, 

 July 14, 1899; Klondike City, July 23, 1899; Bennett City, 

 August 25, 1899 (Williams). 



Calamagrostis Lapponica (Wahl.) Hartm. Dawson, July 

 13, 1899 (Williams). This exactly matches a specimen in the 

 herbarium of Columbia University from Wahlenberg, labeled 

 Arundo Lapponica. It has long been uncertain whether we 

 had this species in this country, but this collection definitely 

 settles the point, if the specimen from Wahlenberg, above 

 referred to, is typical of his species, the original description, 

 however, calling for a taller plant. The grass secured by 

 Mr. Williams is a tufted perennial with culms erect and 3-4 

 dm. tall, the innovations being about one-third as long as the 

 culm with their leaf-blades very narrow and often involute : 

 panicle contracted, 7-9 cm. long and 1 cm. or a little more 

 wide, its branches erect : spikelets about 5 mm. long, purple 

 toward the apex, the flowering scale a little exceeding the 

 copious basal hairs and with a rather stout awn inserted at or 

 near the middle and about reaching the apex of the scale. 



Calamagrostis Yukonensis Nash, sp. nov. 



A tall sle'nder perennial with a slender running rootstock, 

 narrow leaf-blades, and marcescent basal sheaths. Culms 

 8-10 dm. tall, erect, the innovations nearly one-half as long 

 as the culms : culm-leaves 2 ; sheaths very rough, much 

 shorter than the internodes ; ligule scarious, about 5 mm. 

 long, decurrent on the sheath ; blades gray-green, erect or 

 ascending, long-acuminate, very rough on the lower sur- 

 face, the upper surface strongly pubescent with short hairs, 

 the longer blades on the innovations about 3 dm. long and 

 2 mm. wide, those on the culm 1-2 dm. long and 3-4 mm. 

 wide: panicle 8-15 cm. long, contracted, its apex sometimes 

 nodding, the branches erect, fascicled, strongly hispidulous, 

 the longer ones 3-4 cm. long, naked at the base : spikelets 

 numerous, on strongly hispid pedicels usually 1-2 mm. long ; 

 empty scales hispidulous, strongly so on the prominent keel, 

 very acute, yellowish, variegated with purple, the first scale 

 5-6 mm. long, i-nerved, or sometimes with a short lateral 



