MR. G. BENTHAM ON GRAMINEX. 105 
lets vary in the same panicle, one, two, or three to the spike, 
and are themselves polymorphous. Where there are three, I 
have found the lowest empty glume of the lowest; spikelet very 
narrow and awnlike, and very probably that which Kunth has 
described and figured as an awn at the base of the glume; in 
the uppermost of the three spikelets the lowest empty glume is 
similar to the second, the intermediate spikelet being sometimes 
like the upper, sometimes like the lower one. (4) Polyodon, 
H. B. K. (Zriplathera, Eudl.). Spikes few, short, and crowded at 
the end of the peduncle with few spikelets, the flowering glume 
threc-awned, the two or three upper empty glumes each vith 
three or five awns, having together the appearance of a single 
cluster of many awns. We have two species, B. disticha (Poly- 
podon distichum, H. B. K.), including apparently <Atheropogon 
affinis, Fourn. (not Eutriana affinis, Hook. f.), with the spikelets 
including the awns under half an inch long, and B. multiseta ( Eu- 
triana multiscta, Nees), with the spikelets and their awns above 
an inch and a half long, giving the plant the aspect of Boissiera. 
Corethrum, Vahl, is probably the same plant. He received his 
specimen in a collection of Syrian plants sent him by Thouin, 
into which it had probably got misplaced by some carelessness in 
sorting. No special locality is ascribed to it nor any indication 
of the collector; and no plant answering to Vahl's elaborate and 
probably accurate description is known from Syria or any part of 
the Levant. 
14. MELANOCENCHRIS, Nees, comprises three species from 
East India or tropical Africa, closely resembling each other, and 
at first sight having the aspect almost of yopogon but the 
characters are very nearly those of Boucetoua (Atheropogon) ; 
the genus is readily distinguished from both by the linear plumose 
empty glumes. 
The preceding genera have all only a single flower in the 
spikelet, the second, when present, being male only ; in the follow- 
ing ten genera there are at least two, and often several more 
fertile flowers. 
15. Trırocox, Roth (Plagiolytrum, Nees), contains about eight 
East-Indian and tropieal-African species, with the single elon- 
gated terminal spike of Enteropogon, but with several-flowered 
spikelets, and tne flowering glumes more or less three-awned as 
in Trichloris, Triraphis, ete., the lateral awns sometimes reduced 
almost to teeth. 
