a 
STUDIES IN THE COMPOSIT 2. 45 
From these four Prionopsis ciliata is distinguished as a 
generic type by no more striking characters than an annual 
root, serrated foliage, and a coarser pappus; and this again 
, might be joined to another monotypic genus, Xanthisma, 
but for the still coarser, even paleaceous-aristate pappus of 
the latter. 
Having been for a long time in a state of hesitancy 
between uniting the six species under the oldest name, 
Xanthisma, and receiving them as of three genera, two of 
which are monotypic, I now choose, not without some re- 
luctance, the latter alternative, taking for the name of the 
new genus that which Nuttall offered as subgeneric under 
Stenotus, namely, 
OONOPSIS. 
Plants with equably leafy upright stems, usually tufted, upon 
a ligneous caudex or crown. Leaves entire; herbage gla- 
brous (except in the typical species). Heads in a terminal 
fastigiate cyme ; radiate (except in the second species). In- 
volucres ovate or broader; bracts of the same not carinate, 
but flat and often 3-nerved, imbricated, subcoriaceous and 
with green-herbaceous tips ending inacusp. Disk-corollas 
subcylindrie, with 5 rather short teeth.  Stamensand styles 
scarcely exserted ; tips of the latter from ovate to subulate, 
shorter than the stigmatic part. Achenes mostly glabrous, 
and pappus coarse, rigid and rather scanty. 
1. O. mULpTICAULIs. Stenotus multicaulis, Nutt., Trans. Am. 
Phil. Soc. vii. 335 (1840). Aplopappus multicaulis, Gray, 
Am. Nat. viii. 212 (1874). Aster multicaulis, O. Ktze., Rev. 
Gen. i. 318 (1891).—A somewhat local mountain undershrub 
of northwestern Wyoming; seldom collected and not yet 
known in good fruiting condition. 
2. O. ENGELMANNI. Bigelovia Engelmanni, Gray, Proc. 
Am. Acad. xi. 75 (1876). Aster Angelandri, O. Ktze., l. e. 
315.—Local on the plains near Hugo, Colorado. 
