328 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
RanaGE: Pacific slope of southern Mexico. 
HERBARIUM SPECIMENS: 
Jauisco: Guadalajara, dry granitic hills, Pringle 4479; hillside, Pringle 11759. 
Rio Blanco, Palmer 304 in 1886. 
Oaxaca: Villa Alta, Liebmann 671. 
2. Tristachya angustifolia sp. nov. 
Perennial; culms loosely cespitose, thickened at base, slender, glabrous, about 1 
meter high; sheaths glabrous; ligule a dense ring of short hairs; blades narrow, glab- 
rous beneath, scabrous above and on the margins, flat, the tip involute and indurated, 
the lower elongated, 3 to 4 mm. wide, the upper reduced to involute points; panicle 
long-exserted, 10 to 15 cm. long, consisting of a few slender branches, the lower as 
much as 6 cm. long, these simple or bearing 1 or 2 ascending branchlets; axis and 
branches glabrous, scabrous toward the apex; spikelets, excluding the awns, about 
2 cm. long, tawny rather than purple, as in 7. lara, the pedicels longer than the 
spikelets; glumes glabrous or scabrous on the nerves above; fertile lemma about 8 
mm. long, strongly appressed-villous on the callus, less so toward the apex and more or 
less glabrate in the middle region, ending in two short-acuminate teeth about 1 mm. 
long; awn flat, stout, once geniculate, the lower portion loosely but firmly twisted, 
brown, scabrous-pubescent, nearly 2 cm. long, the upper portion straight, purplish, 
12 to 15 mm. long. 
Type in the U. S. National Herbarium, no. 301143, collected near Santa Teresa, 
top of Sierra Madre, Tepic, Mexico, August 13, 1897, by Dr. J. N. Rose (no. 2229). 
This species differs from 7. lava in the lower and more slender stems, narrow 
blades, smaller panicle with shorter and ascending branches, the distribution of the 
pubescence on the lemma, and the short-acuminate teeth. In 7. lara the lemma 
is long-villous all over, the hairs on the callus being shorter, and the teeth of the 
lemma longer and awn-pointed. 
Rance: Known only from the type collection. 
8. Tristachya laxa Scribn. & Merr. U. S. Dept. Agr. Div. Agrost. Bull. 24: 24. f. 7. 
1901. P 
Type locality, ‘‘State of Durango,”’ the type specimen collected in the southern- 
most tip of the State, by Rose (no. 2334). 
RanGE: Known only from the type collection. 
81. DANTHONIA DC. Fl. Franc. 3: 32. 1805. 
1. Danthonia mexicana Scribn. Proc. Acad. Phila. 1891: 301. pl. 13. f. 7, 7b. 1892. 
Type locality, ‘‘dry limestone ledges, Carneros Pass,’’? Coahuila, the type speci- 
men collected by Pringle (no. 3279). 
RanGeE: Highlands of central and southern Mexico. 
HERBARIUM SPECIMENS: 
CoanuiLa: Carneros Pass, limestone ledges, Pringle 3279. 
Puesta: Tehuacin, limestone hills, Pringle 9551, 6767. 
82. MICROCHLOA R. Br. Prodr. Fl. Nov. Holl. 208. 181°. 
1. Microchloa indica (L. f.) Kuntze, Rev. Gen. Pl. 37: 356. 1898. 
Nardus indicus L. f. Suppl. Pl. 105. 1781, 
Type locality, ‘“Tanquebaria,’’ India. 
RanaeE: Warmer parts of both hemispheres. 
HERBARIUM SPECIMENS FROM MEXICO: 
Lower CauirorNiA: Sierra de San Francisquito, Brandegee in 1899. El Taste, 
Brandegee in 1893. La Chuparosa, Brandegee in 1893. 
CurguanHua: Chihuahua, dry gravelly soil, hills and plains, Pringle 425. 
