ME. a. BENTHAM ON GHAMINE^. 61 



13. CiBiSTAOHNE, 13 a genus I have proposed for two plants, 

 one from East India, the other from tropical Atrica, which have 

 something of the aspect of Sorghum tropicum ; but the spikelets 

 all hermaphrodite, and never in pairs, remove them from the 

 Andropogoneae to the TristegineEe. I purpose figuring the genus 

 in the forthcoming part of Hooker's loones. 



Tribe V. Zotsiej3. 



I have composed this tribe of two groups or subtribes, which 

 might perhaps have been regarded as separate tribes, although the 

 difierence between the two is only that which lies between the 

 Cenchrus group and Panicese proper. In the first group, Anthe- 

 phorecB, the spikelets disarticulate from the rhachia of the inflo- 

 rescence or from the pedicels in little clusters of two to six, or 

 very rarely more ; in the other group, or Zoysiece 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 

 Andropogonese, sometimes slightly approaching that of Paniceae, 

 but the pedicels are singly scattered or alternate along the inar- 

 ticulate rhachis of the spike or general inflorescence. The An- 

 thephoresB have hitherto been usually placed in Panicese, as having 

 nearly the inflorescence of Genehrus, but of which they have 

 not the hardened inner fruiting glume ; the Zoysiese proper have 

 mostly been considered as Andropogonese, from which they dififer 

 in inflorescence. Of the twelve following genera, the first six 

 belong to Anthephoreaj, the remaining six to Euzoysiese or 

 Zoysieae proper. 



1. HiLAEiA, H. B. K., in which I should include Pleuraplds of 

 Torrey, and, judging from the figure and description, Sexarrhena 

 of Pros], 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 

 difiierent species, or even in difierent 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 flower, 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. JOrEN. — BOTANT, VOL. IIX. O 



