GRIFFITHS—THE GRAMA GRASSES. 367 
Atheropogon humilis Spreng. Syst. Veg. 1: 293. 1825. Based upon Chondrosium 
humile H. B. K. 
Eutriana humilis Trin, Gram. Unifl. 239.1824. Based upon Actinochloa humilis Willd. 
Chondrosium? simplex Kunth, Rév. Gram. 1: 94. 1829, 
Based upon Bouteloua simplex Lag. 
Bouteloua humilis Hieron. Bol. Acad. Cienc. (Cérdoba) 
4:495. 1882. Based upon Chondrosium humile Beauv. 
Bouteloua brachyathera Philippi, Anal. Mus. Nac. Chile 
(Bot.) 8: 85. 1891. The type, no. 287 of Philippi’s herba- 
rium, has been examined. @ 
Bouteloua rahmert Philippi, Anal. Mus. Nac. Chile (Bot.) 
8:85. 1891. Herb. Philippi, no. 268, Province of Terapaca, 
Chile, is the type. It has been through my hands and 
I find it a very good match for a specimen in the U. 8. 
National Herbarium collected by Rusby (no. 34) near 
Yungos; Bolivia, in 1885. 
DESCRIPTION. 
Fig. 28.—Bouteloua simplex. 
Spikelet. Scale 7.5. From 
typespecimen of B.rahmeri. 
A prostrate or ascending, spreading, smooth annual, 20 
to 25 cm. high; culms geniculate or ascending, seldom 
branched; sheaths smooth, deeply striate, rather loose, the 
ligule a conspicuous ring of short, white hairs; blades not abundant, short, narrow 
and inclined to be involute, about 3 cm. long; spikes terminal, normally 1 but some- 
times 2 to 4, congested at the apex 
of the culm, varying from 2 to 4 
cm. long, straw colored to pur- 
plish-tinged; spikelets commonly 
about 50, about 8 mm. long, in- 
cluding the awns, pectinate, con- 
sisting of a lower perfect floret 
and a rudiment; glumes sharply 
and hispidulously keeled, other- 
wise smooth, the lower about 3 
mm., the upper 5 to 6 mm. long; 
lemma, including awns, about 6 
mm. long, covered on the back 
with a long, scattered pubescence, 
3-awned, the central awn 2 mm. 
longer than the lateral; palet 
smooth, obovate, awnless; rudi- 
ment consisting of 3 hispid awns, 
5 or 6 mm. long, together with a 
few scales at base borne upon a 
hairy, tufted pedicel about 1 
mm. long; caryopsis more or less 
triangular in vertical section, 
Fig. 29.—Bouteloua simplex. a, Spikelet; 6, c, lemma and 
two views of palet of first floret; d, rudiment. a, Scale 7.5; 
b-d, scale 15. From type specimen of B. brachyathera. about 1.5 to 1.75 mm. long, 
slightly curved, the scutellum 
covering about two-thirds of the ventral surface. (FIGURES 28, 29.) 
This description is drawn from Miguel Bang’s no. 81, in the John Donnell Smith 
Herbarium, from the vicinity of La Paz, Bolivia, altitude 10,000 feet. The original 
4 See discussion, p. 368. 
9368°—12——3 
