6 



flowering glumes, including the very sharp-pointed or subulate teeth, 5 mm. 

 long, thinly pilose, hairy on the back, more densely so on the margin. Cal- 

 lus with a few short hairs. Awn about 7 mm. long. Teeth at the apex of 

 the flowering glume subulate, 1.5-2 mm. long. 



Type specimen No. 6140, Aven Nelson and Elias Nelson, collected on the dry 

 slopes about the geyser formations in Norris basin, Yellowstone Park, July 

 25, 1899. Same locality. No. 169 E. D. Merrill, August, 29, 1900. Other 

 specimens examined, apparently belonging to this species, are No. 307, 

 "Williams and Griffiths, collected near the edge of Lolo Hot Springs, Mon- 

 tana, September 17, 1898. This is a small form, 12-24 cm. high. No. 449, 

 David Grifiiths, collected in abundance in ravines near Sundance, Bear 

 Lodge Mountains, Wyoming, August 9, 1897 ; No. 896, David Grifiiths, Sun- 

 dance, Bear Lodge Mountains, Wyoming, 1898; No. 982, David Griffiths, 

 collected in clearings in parks. Bear Lodge Lountains, Sundance, Wyoming, 

 July 21, 1898 



This species is most closel> related to Danthonia spicata of the East, from which 

 it may be distinguished by its more rigid and erect habit, larger spikelets, 

 broader and more conspicviously nerved empty glximes, and larger flowering 

 glumes, the teeth of which are much prolonged and subulate iiointed. The 

 flowering glumes are also much more conspicuously hairy above on the back 

 and margins. 



In the latter part of August, 1900, I found this grass growing on geyser forma- 

 tions in the Norris basin, doubtless in the same locality as that from which 

 the type was collected. It grew in scattered tvifts in the white shelly depos- 

 its close to the geyser, where one would scarcely expect to find any vegeta- 

 tion at all, and, in fact, where there was little else than this grass to be 

 found. The specimens from Montana, above cited, were collected within 

 two feet of Lolo Hot Springs. The differences in the spikelets between this 

 plant and Danthonia spicata of the East, together with the geographical 

 range and peculiar habitat, are our reasons for distinguishing it as a species. 



Danthonia intermedia Vasey. 



This species was described by Dr. Vasey ^ from specimens collected at Mount 

 Albert, Lower Canada, July 26, 1881, by O. D. Allen, and the original 

 description reads in part as follows : 



"Radical leaves, 6 to 10 inches long, narrow; cauliue leaves, 2 to 6 inches, 

 pubescent, especially on the sheaths." 



The material in the National Herbarium shows wide variation in the character 

 of the pubescence. In the type specimen the long white hairs are but 

 sparsely scattered on the sheaths and under surface and margins of the 

 leaves. In other specimens (Griffiths, 486, and Henderson, 3064b) the pubes- 

 cence is dense and shaggy, while on the other hand specimens not otherwise 

 distinguishable (Henderson, 1315, 3064a; Williams, 2770) are quite destitute 

 of hairs, except at the throat of the sheaths and on the leaves of the sterile 

 shoots, and in the latter instance they are very scattering and easily over- 

 looked. The species also varies considerably in the width of the leaves and 

 size of the spikelets. 



Specimens examined: Canada: Mt. Albert, O. D. Allen, July 26, 1881; (type) 

 No. 16 and 31, J. Macoun, August 26 and 27, 1882; mountains north of Grif- 

 fin Lake, British Columbia, 46a., J. Macoun, August 5, 1899; Milk River 

 Ridge, Alberta, No. 13070, J. Macoun, July 19, 1895; head of Qu'Appelle, 

 Great Plains, No. 120, J. Macoun, July 11, 1879. 



Washington: Stevens Pass, Cascade Mountains, No. 760, Sandberg & Lei berg, 

 August 16, 1893 ; Loomiston, No. 553, A. D. E. Elmer, August, 1897. 



' Bui. Torr. Bot. Club. 10 : 52. 1883. 



