GRIFFITHS—THE GRAMA GRASSES. 355 
consisting of one spikelet, the rachis prolonged 1 to 2mm. beyond; spikelet 2-flowered, 
the lower floret perfect, the upper reduced to a 3-awned rudiment; glumes minutely 
hispidulous on the keel, acuminate, the first 2 to 3 mm., the second 4 to 5 mm. long, 
very short-awned or merely acuminate; lemma ovate, indistinctly 3-nerved, especially 
below, 3-toothed at the apex, rarely awned; palet 2-nerved with 2 short awns at the 
apex; rudiment consisting of 3 sca- 
brous awns about 7 mm. long, upon 
a naked stipe 3mm. long; caryopsis 
not seen. (Fiaure 19.) 
This species is common upon the 
highlands of central Mexico, espe- 
cially from Hidalgo to Oaxaca, and 
extends far into Guerrero and west- 
ern Jalisco. It is well represented 
in herbaria by Pringle 7482, 870, 
and 9573, and Nelson 1842, which 
are typical. Miguel Bang’s no. 1307 
in Plantae Bolivianae, from Sorata, 
Bolivia (distributed by Britton and 
Rusby), and Schop’s no. 740 are both 
immature. The latter probably be- 
longs here, but the former is doubt- 
fully referred to this species. 
HERBARIUM SPECIMENS. 
Mexico: Pringle 9573, El Salto; 8708, 
near Jojutla; 4792, Los Sedas, 
Oaxaca. Nelson 1842, Domin- 
guillo; 1542, Valley of Oaxaca. 
Conzattti & Gonzalez 265, Los 
Sedas. Schott 740, Yucatan. 
ee aa ES 
PENTARRHAPHIS H.B. K. 
Pentarrhaphis H. B. K. Nov. Gen. 
& Sp. 1: 177. pl. 60.1816. A mono- 
typic genus based upon P. scabra. 
Polyschistis Presl, Rel. Haenk. 
1: 294. pl. 41. f. 12-18. 1830. Based 
upon P. paupercula, 
Strombodurus Willd.; Steud. Nom. 
Bot. ed. 2. 2: 299.1841. This is 
listed as a synonym of Pentar- 
rhaphis, and the single species S. 
gracilis Willd. is referred (page 647) 
; . 19.— Triaena juncea. a, Spikelet; b,c, lemmaand palet 
to Pentarrhaphis scabra H. B. K. *3:19 , 3 b,c, pa 
The initi i” 1 { the 1 K of first floret; d, rudiment. a, Scale5; b-d, scale1l0. From 
(The initial letter of the latter — Gpigims si22. 
generic name is misprinted ‘‘D”.) 
Species with small, woolly spikes consisting of 2 spikelets, one of these sometimes 
aborted, approximate on a rachis ending in a forked or bifid prolongation; first glume 
of each spikelet reduced to scarcely more than a straight awn; these together with 
the bifid rachis appearing like a cluster of awns at the base of the spikelet; spikelets 
2-flowered. 
