302 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
538. Muhlenbergia straminea sp. nov. 
Tufted stramineous perennial, the base more or less rhizomatous; culms erect, flat- 
tened, smooth below, scabrous above, 50 to 80 cm. high; sheaths scabrous, the lower 
with age becoming papery, flat and ribbon-like; ligule membranaceous, 3 to 12 mm, 
long; blades scabrous, 2 mm. wide, flat or usually involute, about as long as the 
culms, tapering into a long, slender, flexuous point; panicles narrow, tawny, 10 to 20 
cm. long, the branches appressed, rather densely flowered, the lower 4 to 7 cm. long, 
the stout branchlets and short pedicels scabrous; glumes nearly equal, scabrous, 
tawny, rather papery, narrow, acuminate, 4 to 5 mm. long, the first 1-nerved, the 
second 3-nerved; lemma scarcely so long as the glumes, 3-nerved, villous with white 
hairs below, scabrous above, tapering into a slender flexuous awn 5 to 15 mm, long, 
the callus broad and short; palea a little shorter than the lemma, villous below and 
scabrous above. 
Type in the U. S. National Herbarium, no. 691888, collected in the western Sierra 
Madre at Tecorichu, Chihuahua, in pine and oak woods, 2,200 meters altitude, 
April 10, 1906, by R. Endlich (no. 1210). 
This species is distinguished by the stramineous appearance of the glumes and 
foliage and by the flat, ribbon-like lower sheaths, which withdraw from the culms 
and become spirally twisted or curled like shavings, The long, papery glumes indi- 
cate an affinity with Triniochloa, but it is distinguished from that genus by the ter- 
minal awn of the lemma. It appears to be most nearly allied to M. longiglumis. 
The only additional specimens examined were collected in the same region at 
Tierra Colorada by Endlich (no. 1226, 1210a). One of these specimens (no. 1210a) 
has deformed spikelets. The specimens in the United States National Herbarium 
are small portions of those in the herbarium of the Berlin Botanical Garden and were 
received through the courtesy of Dr. I. Urban. 
54. Muhlenbergia enervis (Scribn.). 
Muhlenbergia gracilis var. enervis Scribn.; Beal, Grasses N. Amer. 2: 242. 1896. 
Type locality, ‘‘Mexico,”’ the type specimen collected on dry ledges, Sierra Madre, 
Chihuahua, by Pringle (no. 1413). 
Rance: Known only from the type collection. 
55. Muhlenbergia palmeri Vasey, Bull. Torrey Club 3: 231. 1886. 
Type locality, ‘‘S. W. Chihuahua,’’ the type specimen collected in 1885 by Palmer 
(no. 16). 
RanGE: Known only from mountains of Chihuahua. 
HERBARIUM SPECIMENS: 
CHIHUAHUA: Southwestern Chihuahua, Palmer 16 in 1885. Wet places, pine 
plains, base of Sierra Madre, Pringle 1417. 
56. Muhlenbergia acuminata Vasey, Bot. Gaz. 11: 337. 1886. 
Type locality, ‘‘New Mexico,”’ the type specimen collected by Wright (no. 1993). 
RanGE: Mountains of New Mexico and south in the highlands to San Luis Potosf. 
HERBARIUM SPECIMENS FROM MExIco: 
CHIHUAHUA: Chihuahua, cool slopes, rocky hills, Pringle 403. 
Coanutta: San Lorenzo Canyon, Palmer 399 in 1904. Saltillo, rich moist soil, 
Palmer 379 in 1898; dry hills, Palmer 416 in 1898. Chojo Grande, Palmer 
341 in 1904. 
San Luis Porosf: San Luis Potosf, Parry & Palmer 969 in 1878. 
57. Muhlenbergia elongata Scribn. in Beal, Grasses N. Amer. 2: 251. 1896. 
Type locality, ‘‘Mexico,’’ the type specimen collected on ‘‘ Ledges, rocky hills near 
Chihuahua” by Pringle (no. 398). 
RANGE: Highlands of Chihuahua. 
