GRIFFITHS—THE GRAMA GRASSES. 389 
by old growth at its base, the leaves are more lax, ascending, and longer, and the 
culms are more leafy above. 
Specimens are abundant in American herbaria. They are usually referred to B. 
burkit and B. trifida in about equal numbers. The range of the species is from the 
Rio Grande region of Texas southward to San Luis Potost and westward to Tucson, 
Arizona. 
HERBARIUM SPECIMENS. 
The following are typical of B. burkw: 
Texas: Reverchon 162, Coleman and Tom Green Counties; 13614 and 1361,¢ Llano; 
1408, Sabinal Canyon; 3440, Upper Concho, in Curtiss N. Amer. Plants. Jermy, 
Bexar County. Smith 97, San Diego. Tracy 8230, Colorado; 8896, Kingsville. 
Nealley, Cotula, 1888. Piper, Kingsville, 1906. Letterman, Laredo, July, 1882. 
Berlandier 1427. 
Mexico: Pringle 1974 and 11735, Monterey; Palmer 370, Victoria. 
The following herbarium specimens are typical of B. trifida (Pu. 74, A.): 
Arizona: Pringle, mesas near Tucson, 1884. Griffiths 2448, Tucson. 
New Mexico: Wright 2022 of 1851-52. 
Texas: Vasey, El Paso, 1881. Reverchon » 1408 (Texas Plants), Sabinal Canyon. 
Mexico: Palmer 522 and 402, Saltillo. 
The following specimens appear to stand mid- 
way between the two forms in some characters, 
usually due to long awns combined with softness 
and laxity of leafage: 
Arizona: Lemmon, Hackberry 1889. 
Texas: Canby 270, Spofford Junction. Reverchon 
37; 361, Llano (Texas Plants); 1408, Sabinal 
Canyon. Jermy 212, Bexar County. Plank, 
El Paso, 1894; 1, Llano. Havard 30, mouth of 
Pecos. Mearns 1215, Fort Clark. 
Mexico: Pringle 412, Chihuahua. Palmer 552, Vic- 
toria; 1355, Monclova. Parry & Palmer 945, 
San Luis Potosi. Wilkinson, Santa Eulalia 
Plains, Chihuahua, 1885. Mearns 1201, La 
Noria, Sonora. 
14. Bouteloua sonorae sp. nov. Fic. 43.—Bouteloua sonorae. a, Spike- 
let; 6,c,lemma and palet of first 
DESCRIPTION. floret; d,e,rudimentary lemma and 
palet of second floret; /, rudiment of 
A low, spreading, or half-erect perennial, 12 to 15 te ore sie tbr bch, poale 10. 
em. high; culms simple, stoloniferous or simply from type specimen. 
geniculate; sheaths close, striate, smooth, the ligule 
a rather long fringe of white hairs; blades mostly radical, narrow, short, acuminate, 5 to 
10 em. long, decreasing upward to often 1 cm. long, revolute; panicle racemose, about 
4em. long; spikes 2 to4, mostly 4, about 12 to 14 mm. long, recurved at the apex; spike- 
lets about 30, pectinate, about 2.5 mm. long, consisting of a lower perfect floret and an 
upper rudiment; glumes smooth except for a few long white hairs on the keel, not 
awned, the second 1.5mm. long, the first a little shorter; lemma hairy, 3-nerved, shortly 
3-awned, 2.3 to 2.5 mm. long, including awns; palet concave, shortly 2-awned, a trifle 
shorter than its lemma; rudiment of 3 awns interspersed with short, blunt scales 
upon a short, hairy-tufted stipe, about 0.5 mm. long; caryopsis not seen. (Ficure 43.) 
a Typical B. burkii and B. trifida are on the same sheet of no. 1361, Texas Plants. 
b Three sheets of this are placed in as many groups. 
