112 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
might have been expected in Doctor Rydberg’s Flora of Colorado, 
and their omission may have resulted from their being overlooked 
within that State; or they may be plants which do not range so far 
north. While the flora of those mountains which are the southern 
extension of the Sangre de Cristo Range, and form the great mass of 
peaks lying between Santa Fe and Las Vegas, is similar to that of 
the mountains of southern Colorado, there are found in their canyons 
and on their slopes more than a few well-known plants which appar- 
ently do not occur in Colorado. 
The types of the following new species are all in the National 
Herbarium. With a few exceptions, which are plainly indicated, 
all are from New Mexico. In nearly every case we have had access 
to an abundance of material, consisting either of several collections 
from adjacent or distant localities or of additional individuals of the 
type collection. In every instance in which the material was scanty 
the plant was one so strongly marked that its specific distinctness 
could not be questioned. 
Nearly all the new species, as well as new names, are published 
jointly by the two authors. Exceptions are clearly indicated. We 
have included descriptions of several plants determined as new spe- 
cles by Dr. E. L. Greene, but never described. These are principally 
from the collections made by Mr. O. B. Metcalfe. Many other plants 
of Mr. Metcalfe’s collections, distributed under new names, we have 
associated with published species. The present paper includes also 
descriptions of several new species detected by Prof. J. J. Thornber, 
of the University of Arizona, in connection with his work upon the 
flora of that State. 
DESCRIPTIONS AND NEW NAMES. 
POACEAE. 
Aristida pansa Wooton & Standley, sp. nov. 
Erect, cespitose perennial, 25 to 40 em. high, forming tufts 10 cm. or more in 
diameter; culms simple, rigid, though slender, minutely puberulent, glabrous 
in age, somewhat striate; leaves mostly basal, narrowly linear, involute, 
striate, puberulent throughout, more or less curled; sheaths of the basal leaves 
overlapping, 1 to 2 cm. exposed, those of the culms 4 to 5 cm. long, closely in- 
vesting the culms; ligule a tuft of very fine, white hairs encircling the sheath 
both inside and out; blades 5 to 15 cm. long, those of the upper culms shortest; 
panicle at first strict, 10 to 20 cm. long, bearing many more or less crowded 
spikelets, at last spreading, the branches rigidly ascending, mostly in pairs; 
rachille slender, almost capillary, bearing several crowded small spikelets; 
glumes slightly unequal, the first shorter, glabrous, narrowly lanceolate, acumi- 
nate, 1-nerved, the nerve sometimes slightly produced, purple when young, yel- 
lowish in age, the second glume about the length of the lemma; this 8 to 10 
mm. long, attenuate upwards, slightly twisted at maturity, scabrous above, 
callous and bearing a tuft of white hairs; awns short, 10 to 20 mm. long, at 
