MR. G. BENTHAM ON GRAMINE £. 61 
13. CLEISTACHNE, is a genus I have proposed for two plants, 
one from Fast India, the other from tropical Atrıca, which have 
something of the aspect of Sorghum tropicum ; but the spikelets 
all hermaphrodite, and never in pairs, remove them from the 
Andropogones to the Tristeginew. I purpose figuring the genus 
in the forthcoming part of Hooker's Icones. 
Tribe V. ZoYSIEZ. 
I have composed this tribe of two groups or subtribes, which 
might perhaps have been regarded as separate tribes, although the 
difference between the two is only that which lies between the 
Cenchrus group and Panicee proper. In the first group, Anthe- 
phoree, the spikelets disarticulate from the rhachis of the inflo- 
rescence or from the pedicels in little clusters of two to six, or 
very rarely more; in the other group, or Zoysiec proper, the 
spikelets are solitary, or very rarely two together on the pedicels. 
In both groups the structure of the spikelets is generally that of 
Andropogone&, sometimes slightly approaching that of Panices, 
but the pedicels are singly scattered or alternate along the inar- 
ticulate rhachis of the spike or general inflorescence. The An- 
thephorex have hitherto been usually placed in Panicee, as having 
nearly the inflorescence of Cenchrus, but of which they have 
not the hardened inner fruiting glume; the Zoysiex proper have 
mostly been considered as Andropogone&, from which they differ 
in inflorescence. Of the twelve following genera, the first six 
belong to Anthephorew, the remaining six to Euzoysiex or 
Zoysieze proper. 
1. Hırarıa, H. B. K., in which I should include Pleyraphis of 
Torrey, and, judging from the figure and description, Hexarrhena 
of Pres], comprises five or six species dispersed over the Mexicano- 
Texan region, extending into California. Although the forms 
and proportions of the glumes of each spikelet vary much in the 
different species, or even in different spikes of the same plant, the 
genus as a whole is a natural one, and readily recognized by 
each cluster consisting of three spikelets, the central one con- 
taining a single fertile lower, either female or hermaphrodite, the 
two lateral ones each with two male flowers. The spikelets are 
often so closely sessile in the cluster, that it requires some care 
to ascertain which glumes belong to each cluster, and the pairs 
of male triandrous flowers of the lateral spikelets have sometimes 
been described as single hexandrous flowers. The species I have 
LINN, JOURN.—- BOTANY, VOL. XIX. a 
