120 MR. G. BENTHAM ON GRAMINEE. 
to two or one. The habit is nearly that of the section Bromelica 
of Melica. 
Our seventh subtribe Centothecee is formed of a small number 
of tropical grasses, several of which have been occasionally re- 
ferred to Bambuse&, but expelled from that tribe by all who have 
specially worked at it. The structure of the spikelet is that of 
some Eufestucex or Melicer ; but the foliage is unusual, the 
lamina of the leaf is broad and flat, and between the numerous 
longitudinal veins are small transverse veinlets not observed in 
any others of the Order except in a few Bambusex. There is, 
however, none of that articulation of the lamina on the leaf-sheath 
which is almost universal in the latter tribe. The Centothece& 
comprise five genera. 
45. CENTOTRECA, Desv., has two or three species from the tro- 
pical regions of the Old World. They are tall grasses with a 
loose panicle, the spikelets awnless with usually more than two 
flowers, without any, or with only one empty glume above them. 
In the common C. lappacea, Desv., the flowering glumes have on 
their back a few reflexed rigid hairs or bristles; and that has 
been generally relied upon as the essential character of the genus ; 
but the bristles are sometimes reduced to one or two minute 
tubercles, or even wanting, and in an African species (probably 
the Poa mucronata, Beauv.) there is no trace of them, and yet 
the plant is in all other respects an undoubted Centotheca. 
46. OzTHOCLADA, Beauv., is a single tropical-American species, 
with the habit, foliage, and inflorescence of Centotheca ; but the 
spikelets contain only one, or rarely two, fertile flowers, the second 
flower being usually male only ; the glumes have never the re- 
versed bristles of Centotheca; and the spikelets appear to be fre- 
guentiy unisexual. 
47. LorHaTHERUM, Brongn. (Acroelytrum and Allelotheca, 
Steud.), has one, or perhaps two, species from tropical and 
Eastern Asia. The habit, foliage, and inflorescence are those of 
Centotheca and Orthoclada ; but above the single fertile flower 
are several small empty, very shortly-awned glumes, densely 
crowded in a little uuilateral tuft or crest, bringing the genus 
into connection with Melicez. 
48. SrREPTOGYNE, Beauv., is a single species sparingly scat- 
tered over East India, tropical Afriea and America, and the 
southern states of North America, allied perhaps in some re- 
spects to Lophatherum, but quite isolated in habit and a variety 
