418 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
spikelets 3 to 5, consisting of a lower perfect floret and an upper rudiment; glumes 
narrow, hispid, keeled, the first about 3 mm., and the second about 5 mm. long, 
smooth, with 3 short, hispid awns, the central awn not over 0.5 mm, longer than 
the lateral; palet the same length as its lemma, with two short awns from the two 
nerves; rudiment usually consisting of a single 3-awned lemma, the central awn 
being by far the most important, often 9 to 10 mm. long, the lateral awns only 2 mm. 
long, infolded; caryopsis flattened, 1.75 mm. long, 0.5 mm. wide, the small scu- 
tellum covering only about one-third of the ventral surface. (FiaureE 61.) 
The description is drawn from Snodgrass & Heller 393, James Island, Galapagos, 
April, 1899. This appears to be a good, average specimen, although it does not cover 
all of the many variations. The spikelet described is from the middle of the spike. 
In the lower spikelet the rudiment is usually much smaller than described, at times 
even reduced to a single awn half as long as the perfect floret. It is exceedingly 
variable and is more closely related to B. curtipendula than to any other species, 
The Hopkins Galapagos Expedition furnished a fine series of specimens, the best 
representatives of which are in the Gray Herba- 
rium, Some of them might be considered an- 
nual, but no. 507 is clearly perennial. In general 
aspect this certainly looks like B. curtipendula. 
35. Bouteloua uniflora Vasey. 
Bouteloua uniflora Vasey, Bot. Gaz. 16:26. 
1891. The type is Nealley 222, Crockett County, 
Texas, 1890, in the National Herbarium. See 
also U.S. Dept. Agr. Div. Agrost. Bull. 7: 212, 
f. 194. 1897. 
DESCRIPTION, 
Fig. 62.—Bouteloua uniflora. a, Spike, of A tall, smooth, tufted, erect perennial, with 
single spikelet with prolongation of the habit and general appearance of B. curtipen- 
rachis; 6, c, lemma and palet; d, rudi-  j7q- culms simple or branched at the very 
ment. a, Scale 5; b-d, scale 13. From . . 
type specimen. base, 35 to 50 cm. high; sheaths striate, smooth 
or minutely rough-hispid under a lens, the ligule 
reduced to a ring of short, flexuous, white hairs; blades variable, from 2 to 10 cm. 
long, the longest above, striate, minutely hispid, especially on the upper surface 
and on the involute edges, the latter being also sparsely papillose-ciliate; panicle 
racemose, exactly like that of B. curlipendula excepting for the smaller spikes; 
spikes 25 to 35, 8 to 9 mm. long, consisting of a 1-flowered spikelet and a hispid, 
closely appressed prolongation of the rachis, about 4 mm. long; second glume 7 to 8 
mm. long, | mm. wide, acuminate, the first about 3 mm, long, 0.8 mm. wide, with 
a more rounded apex; lemma smooth, 3-nerved, very short-awned or awnless, about 
6 mm. long, with a narrow, 2-toothed, smooth palet, about 5 mm. long; rudiment 
consisting of a single, simple, hispid awn about 4 mm, long; caryopsis not known, 
(FIGURE 62.) 
The specimen is immature, and it is barely possible that it may turn out to be an 
aberrant form of B. curtipendula. Bigelow, “Rio San Pedro, Texas,’? November 5, 
1850, in the herbarium of 8. M. Tracy, from the Thurber Herbarium, is the same as 
the type in every floral detail, but the spikes are more numerous. No collections 
other than these two have been seen. 
