654 RYDBERG: Rocky MOUNTAIN FLORA 
linear, the outer obtuse, the inner acute, green or the inner white 
on the sides below, pubescent on the back, but not bristle-pointed ; 
rays purple, about 8 mm. long and 1 mm. wide ; achenes pubescent. 
This is nearest related to A. griseus Greene, but differs in the 
small size, the narrow short sessile leaves, and the pubescence 
which is not reflexed on the lower part of the stem. A. grzseolus 
grows on the higher mountains of Colorado. 
CoLtorapo: Mt. Harvard, 1896, Clements 37 (type); Twin 
Lakes, 1896, Shear 34099. 
“Aster Underwoodii sp. nov. 
_ Perennial with a horizontal rootstock ; stems simple up to the 
inflorescence, 2-3 dm. high, often purplish, more or less hirsute- 
strigose ; lower leaves spatulate or oblanceolate, tapering into a 
winged petiole, glabrous except the ciliolate margin or slightly 
pubescent when young; the other stem-leaves sessile and the 
uppermost linear-lanceolate ; inflorescence racemiform or corymbi- 
form with 4-8 heads ; these fully 1 cm. high; bracts oblanceolate, 
the outer obtuse, the inner acutish, all with a rather thick green 
tip, pubescent on the back; rays purple or bluish, about 1 cm. 
long and I-1.5 mm. wide ; achenes hirsute. 
This is related to A. adscendens and A. Nelsonii. From the 
former it differs in the hairy bracts and from the latter in the broad 
leaves. It suggests also A. griseus, but has shorter and almost 
glabrous leaves. It grows at an altitute of 2500-3000 m. 
Cororapo: Ironton Park, 1901, Underwood and Selby 318 
(type) ; Eldora to Baltimore, 1903, Zizveedy 5831. 
v Aster Osterhoutii sp. nov. 
Tall, branched and leafy, about 1 mm. high; stem striate, 
glabrous below, hairy in decurrent lines above ; leaves linear or 
linear-lanceolate, 5-12 cm. long, 8 mm. wide or less, scabrous- 
ciliolate on the margin, otherwise glabrous, entire-margined, sessile 
and half clasping ; those of the branches much smaller ; inflores- 
cence open-paniculate ; heads nearly 1 cm. high; bracts in 4-5 
series, the inner linear, acute, the outer oblanceolate, apiculate, 
green and with white margins below ; rays white or oer pinkish, 
nearly 1 cm. long and fully 1 mm. wide. 
This species is related to A. salicifolius, but differs in the narrow, 
thin, entire leaves. Mr. Fernald, to whom some of the specimens 
had been sent, named it A. salicifolius caerulescens Gray, but that 
