MR. G, BENTHAM ON GRAMINEZ, 87 
genus, but in the whole tribe of Agrostex, by the spikelets con- 
taining occasionally two flowers (without awns or continuation of 
the rhachilla) as in Isachnew and in some species of Aira and Col- 
podium ; but the small spikelets and carpological characters are 
quite those of Sporobolus. 
There remain for the EvAGROosTEE, or fourth and last subtribe 
of Agrostes, about sixteen genera, of which the general character 
is a dorsal usually twisted awn on the flowering glume, the grain 
neither so closely enveloped in the fruiting glume as in Stipes, 
nor so readily exposed as in Sporobolez, and the spikelets usually 
small, loosely paniculate, very rarely condensed into a head as in 
Phleoidex ; but there are exceptions to every one of these charac- 
ters, and the limits of the larger genera are so vague as to render 
this portion of the genera of Graminez the least satisfactory of the 
Whole sevies. Of the sixteen following genera, the first seven 
show none of that continuation of the rhachilla beyond the flower 
Which in the others takes the form of a glabrous or hairy bristle 
rarely reduced to a mere tubercle; the last four of the series, as 
well as Triplachne, have, besides the dorsal awn, two or four teeth 
to the glume, sometimes produced into straight awns. A few spe- 
cies or monotypie genera have no awn to the flowering glume, 
but otherwise in the structure of the spikelet are nearer to Agrostis 
than to Sporobolus. 
20. EPrcAwPEs, Presl, about sixteen species from Mexico and 
the South-American Andes, probably reducible to about two 
thirds of that number, is a genus most embarassing to the syste- 
matist ; for it seems to connect Muehlenbergia and Sporobolus with 
Agrostis. 'The chief general feature is the long narrow dense 
panicle with very numerous rather small spikelets, the awn 
of the flowering glume, when it exists, much smaller than in 
Muehlenbergia and often not quite terminal; the unawned species 
distinguished from Sporobolus by the fruiting glume and grain 
nearly those of Agrostis, and from the latter genus by the inflo. 
rescence and by the awn when present being very small and 
almost terminal. Several of the published species, however, are 
unknown to me; and a further study may require considerable 
modification of the generie character and limits. Crypsinaa, 
Fourn., which appears inseparable from Epicampes, is founded 
on the Z. macroura (Cinna macroura and C. stricta, Kunth), a 
Mexican species remarkable for the very long, narrow, almost 
spikelike panicle. Cinna macroura, Thurb., from California, is a 
