286 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
HERBARIUM SPECIMENS: 
LowEr CALIFORNIA: Sierra de la Laguna, Brandegee in 1899. 
CurauaHua: Mifiaca, base of rocky butte, Hitchcock 7741. 
DuraNnco: Otinapa, Palmer 339 in 1906. 
Hmauco: Pachuca, rocky hill, Hitchcock 6749, 6751. Woodlands near Trinidad 
Iron Works, Pringle 13249; Sierra de Pachuca, Rose, Painter & Rose 8744. 
México: Ixtaccihuatl, Purpus 1637. 
TLAXcALA: Contadero, Pringle 8595. 
Puesta: San Luis Tultitlanapa, Purpus 3589. Esperanza, rocky hill, Hitchcock 
6532. 
Oaxaca: Oaxaca, Nelson 1373a. 
3. Oryzopsis florulenta Pilg. Bot. Jahrb. Engler. 27: 26. 1899. 
Type locality, “Columbia: * * * in monte Alto de Pesares supra Popayan,”’ 
the type specimen collected by Lehmann (no. 6980). 
Rance: Mountains, southern Mexico to Colombia. 
HERBARIUM SPECIMENS FROM MEXICO: 
TLAXcALA: Contadero Station, hills, Pringle 8596. 
Pursia: Esperanza, rocky hill, Hitchcock 6493; Seaton 319. 
62. PIPTOCHAETIUM Presl, Rel. Haenk. 1: 222. pl. 37. f. 1—7. 1830. 
1. Piptochaetium brevicalyx (Fourn.) Ricker. 
Stipa brevicalyx Fourn. Mex. Pl. 2: 150. 1886. 
Type locality, ‘‘Circa San Luis de Potosi,” the type specimen collected by Parry 
and Palmer (no. 959). 
Rance: Highlands of central and southern Mexito. 
HERBARIUM SPECIMENS: 
San Luis Potosi: San Luis Potosi, Parry & Palmer 959. 
Hipauao: Pachuca, rocky hill, Hitchcock 6733. Real del Monte, in oak woods, 
Rose, Painter & Rose 8744. 
63. MUHLENBERGIA Schreb. in Gmel. Syst. Nat. 2: 87, 171. 1791. 
KEY TO THE SPECIES. 
Plants annual. 
Awn of lemma short, not longer than the body of the 
lemma (sometimes slightly longer in M. ligulata). 
Glumes ciliate; panicle open, the branches spread- 
INg..-.-----------e ee ee wee e eee eee eee eee eee 1. M. texana. 
Glumes not ciliate. 
Second glume strongly 3-toothed, the teeth about 
equal.......-..------------------------- 8. M. pusilla. 
Second glume not distinctly 3-toothed. 
Lemma entire; panicle green ............-. 3. M. ligulata. 
Lemma bifid, awned from between the short 
teeth; panicle tawny. 
Panicle open....-...-...-.------------ 2. M. flavida. 
Panicle narrow, the branches short and 
appressed ...............--22.205- 2a, M. flavida strictior. 
Awn of lemma more than twice as long as the body of the 
lemma. 
Glumes or some of them awned, the awn as long as 
the body of the glume or longer. 
One glume of some of the upper spikelets of each 
branch long-awned......scseeeeesereeees 4, M, diversighumis, 
