STUDIES IN THE Cowrosrrx,—IV. 
OREASTRUM. 
Acaulescent perennials, with narrow subcoriaceous entire 
leaves and scapiform monocephalous branches from a stout 
somewhat fusiform and not freely branching tap-root. 
Bracts of the involuere narrow, subequal, in about 2 series. 
Rays rather numerous, elongated, purple. Disk-corollas 
tubular-funnelform, 5-toothed and the teeth erect. Style- 
branches filiform to subulate-linear, strongly hirsutulous. 
Achenes subterete, distinctly 5 to 8-costate. Pappusa single 
series of brownish barbellate-scabrous and rather fragile or 
deciduous bristles. 
The two or three species of far-western subalpine plants 
here received in the rank of a genus are related to Aster 
somewhat less intimately than are their Atlantic American 
analogues, the species of Heleastrum. Their ty pe-species, 
when new to botanists, was not at all thought of as a possi- 
ble Aster; and Dr. Gray published it as an Aplopappus; its 
aspect being so completely that of Pyrrocoma that the author 
seems to have had no doubt that its rays, when known 1n 
the fresh state, would prove to be yellow. And now that all 
authorities have found themselves forced to admit yellow- 
rayed and purple-rayed species of astereous plants within the - 
limits of a genus, I have been for several years hesitant — 
between the two alternatives of referring the present type to 
-Pyrrocoma, where Gray at first placed it, and that of propos 
ing for it the rank of a genus. From Aster it is abundantly 
distinct by characters of flower and fruit alone, not to men- 
tion the un-aster-like vegetative peculiarities. The disk- 
corollas in Aster are more deeply cleft and the segments 
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