426 BOTANICAL GAZETTE [DECEMBER 
reached the Himalayas. According to CHEESEMAN,? Deschampsia 
caespitosa macrantha Hack. and Trisetum subspicatum occur in New 
Zealand, and the latter has also been recorded from the antarctic 
regions. Deschampsia caespitosa is in Arctic America, Greenland, 
Novaja Zemlja, and Arctic Siberia, mostly represented by vars. 
brevifolia Trautv. and borealis Trautv. Agrostis canina occurs in 
Greenland and in several forms, but the variety which I collected in 
Colorado is not among these. Professor HackEL, who has kindly 
examined my specimens of Agrostis, thinks that my alpine A. canina 
is nearest to var. pusilla Aschers. et Graebn. 
Tables II and III thus demonstrate the fact that the alpine Gra- 
mineae in Colorado represent an assemblage of several very distinct 
geographical types: some that are endemic to this particular region; 
some that occur also on the Pacific and Atlantic coasts; some that 
have reached the polar regions in certain parts of both hemispheres; 
some that are circumpolar; and finally some that have become 
dispersed throughout the mountainous districts farther south in 
Europe and Asia. Of the 20 species enumerated from the mountains 
of Colorado, 7 are arctic-alpine types. Deschampsia caespitosa and 
Festuca ovina are quite frequent in these alpine and arctic regions, 
but their widest distribution is within the lowlands of the temperate 
zones of both hemispheres; hence they are not “arctic-alpine”’ in the 
strict sense of the word. 
The tribes that are thus represented in this alpine region are 
AGROSTIDEAE (5 spp.), AVENEAE (4 spp.), FESTUCEAE (8 spp-), and 
HorbEAE (2 spp.). They are represented by genera that are really 
cosmopolitan, and from Table III we have seen that some of the 
species are widely distributed in both hemispheres. These data alone 
might suffice to illustrate the principal points in regard to compo 
sition and geographical distribution; but in order to make the illus 
tration more complete, it seems necessary to extend our comparison 
to the grass vegetation in the timbered belts and on the plains below; 
also to the vegetation of alpine regions of other mountains. ad 
Beginning with the species of the spruce zone, it has been stat 
that some of the alpine species are found among them, where they 
become associated with a few types characteristic of the zones 
? CHEESEMAN, T. F., Manual of the New Zealand flora. 1906. 
