SOME ROCKY MOUNTAIN ASTERS. 213 
partieular attention to this genus. But the several species 
attributed to Wyoming are based on material assiduously 
collected by Professor Nelson, and submitted to me for study. 
The Asters of those far-western regions are doubtless not 
as numerous as the eastern representives of the genus, yet 
their number will prove considerable, and perhaps as diffi- 
cult of definition as the eastern. 
I believe that all,or nearly all, the following will be found 
valid species; and it is likely to be long before several of 
them will be better known; for I have obtained them in 
places not easily accessible; but they are excellently repre- 
sented in my herbarium. 
A. DISTICHOPHYLLUS. Low, with many erect leafy and 
usually monocephalous stems rising separately from a sys- 
tem of branching horizontal rootstocks: leaves from oblong- ` 
lanceolate to spatulate-linear, thickly clothing the simple 
stem and diminishing in size upward, all of firm texture, 
pale and glaucesent, also on both faces sparsely and stiffly 
strigose, the entire margins scaberulous, the lower and 
subpetiolate ones with half-clasping base: stem commonly 
reddish and with an appressed whitish pubescence: head 
hemispherical, 4 inch high and $ inch broad: involucre 
comparatively small, its firm erect bracts in about 3 not very 
unequal series, the outer spatulate-oblong, obtuse, herbace- 
ous, the inner more linear, acute, and with narrow green 
tips, all more or less ciliolate: rays 40 or more, purplish. 
On clayey banks below Marshall Pass, southern Colorado, 
4 Sept., 1896, collected only by the writer. A peculiar dwarf 
monocephalous very leafy species, with the numerous leaves 
often appearing in two ranks by a sort of polarity. The 
tallest specimens are hardly six inches high. 
A. vioLACEUs. With the subterranean vegetative system 
