ico n 
MR. G. BENTHAM ON GRAMINES. 39 
glume (corresponding to the third of Panicum) usually eneloses 
a palea or a male flower—a circumstance unusual in the Order, 
where the exposed glumes are almost always empty. From these 
I cannot separate generically the South-A merican Leptocoryphium, 
Nees, which, besides some slight specifie characters, only differs 
from the North- American species in the second glume being con- 
stantly, instead of occasionally only, empty. The genus Authe- 
nantia thus constituted includes three species— A. villosa, Beauv. 
(Aulaxanthus ciliatus, Ell., Panicum ignoratum, Kunth), A. rufa, 
Benth. (Aulaxanthus rufus, Ell., Panicum rufum, Kunth), and 
A. lanata, Benth. (Paspalum lanatum, H. B. K., Milium lanatum, 
Kunth, Z eptocoryphium lanatum and L. molle, N ees). 
4, AMPHICARPUM, Kunth, with spikelets unisexual by abortion 
and a peculiar inflorescence, remains limited to the single North- 
American species on which the genus was founded. 
5. Enrocuroa, H. B. K. (a name having the right of priority 
over GMipachne, Link, and Helopus, Trin.), has the habit rather of 
the section Brachiaria of Panicum than of Paspalum, but wants the 
small lower glume of the former genus, and differs generally from 
both in a peculiar callous thickening of the pedicel at the articu- 
tion. There are, however, a very few species with more or less 
of this callosity, which on other accounts cannot well be separated 
from Panicum. The flowering glume has also the peculiar point 
on the obtuse apex observable in Panicum helopus, Trin., and in a 
few others, and supposed to characterize a section or genus Üro- 
chloa. It is, however, an uncertain character, both in Eriochloa 
and in Panicum. Nearly twenty supposed species of Eriochloa 
have been described ; but the greater number of them are > scarcely 
even varieties of the E. polystachya, H. B. K., which is widely 
spread over the warmer regions of the Old as all as the New 
World, and known under the various names of Z. punctata, E. 
annulata, Ze, There appear also to be at least four really distinct 
species—L. distachya, H. B. K., and Z. grandiflora (Helopus, 
Trin.) from tropical America, Æ. Wak Hochst., from tropical 
Africa, and Z. villosa, Kunth, from eastern Asia. 
6. BECEMANNIA, Host, is a uis species, ranging from eastern 
Europe across Russian Asia to North America. It has been 
usually placed in Phalaridez, a tribe with which it appears to me 
to have but little connection. The habit and inflorescence are 
those of Panicum colonum; but it is exceptional in Panicer as 
having both the flowers hermaphrodite; the lowest flower is, 
