82 MR. G. BENTHAM ON GRAMINEE. 
Spreng., Piptochetium, Presl, and Nassella, E. Desv., is entirely 
American, with the typical character of the genus, and the rha- 
chilla bearing a ring of hairs under the flowering glume. 3. Erio- 
coma, Nutt. (Fendleria, Steud.), differs from Euoryzopsis only in 
the long silky hairs clothing the fruiting glume. 
4. Mrt, Linn., was formerly extended to several unawned 
Panice with only two empty glumes, but is now reduced to five 
or six European or temperate Asiatic species, one of which is 
also spread over North America, all removed from Panicace& as 
haying the empty glumes persistent below the articulation. They 
differ from Oryzopsis chiefly in their obtuse absolutely unawned 
flowering glume. 5. Actacuye, Benth., is a single dwarf tufted 
dicecious grass from the higher mountains of Peru and Colombia. 
The female individual, with only one spikelet terminal on the pe- 
dunele, is fully described and figured in the last part of Hooker’s 
*Ieones) The male plant, if correctly matched, of which I am 
by no means certain, has a loose almost simple panicle with pre- 
cisely the glumes of the female, but enclosing stamens only. In 
the few specimens seen the leaves are much longer than in the 
numerous females from various localities, which makes me rather 
doubt the specific identity of the two. 
6. MUEHLENBERGIA, Schreb., has nearly sixty known species, 
chiefly American, extending from the Andes of South America 
over the northern continent generally, with a very few from 
central or eastern Asia. They connect, in many respects, Stipa 
with Agrostis. In general they come very near in technical 
character to the smaller-flowered Stipe, differing in the still 
smaller spikelets with thinner though still closely appressed and 
narrow fruiting glumes, and usually with a more or less hairy 
rhachilla. From Agrostis and its immediate allies they may be 
readily distinguished by this narrow appressed fruiting glume 
with a terminal never dorsal awn; a very few unawned species 
are scarcely separable from Epicampes, except by the shape of the 
glume. There is a considerable variety in the inflorescence and 
in the proportions of the glumes, but nothing definite enough to 
establish good sections, although several separate genera have 
been proposed. In the original M. diffusa, Schreb., and its im- 
mediate allies, the panicle is usually long, narrow, and dense, 
and the lower empty glumes are very minute ; whilst in Trinius's 
proposed section Acroxis both the lower glumes or one only of 
them are nearly as large as the flowering one; but throughout the 
