124 ME. G. BENTHAM ON GEAMIJTBi. 



spikeleta almost sessile. Galoiheca, Desv., with a loose spreading 

 panicle, has broadly scarious awned glumes. 



60. ScHisMUS, Beauv. {Electra, Panz., Hemisacris, Steud.),ha8 

 three or four species, one of them widely spread from the Medi- 

 terranean region, eastwards to Afghanistan and Arabia and 

 westwards to the Canary Islands, the others South African. All 

 are annuals with a narrow panicle, and distinguished by the long 

 empty glumes quite enclosing the flowering ones. 



61. Nephelochloa, Boiss., limited to the original Oriental 

 species, is a very elegant little grass with the habit of Aira invo- 

 lucrata, and is figured in the last part of Hooker's Icones. The 

 species added to the genus by G-risebach, for which he was obliged 

 to alter Boissier's character, are now restored to Poa. 



62. Poa, Linn., is a cosmopolitan genus, chiefly extratropical, 

 which, after frequent extensions and reductions, has now become 

 fairly limited to a series of about eighty species. They form a 

 group natural enough as to the great majority of species, dif- 

 fering from JSragrostis in their five-nerved flowering glumes, from 

 Glyceria and Festuca in their glumes keeled from the base ; but 

 here, as elsewhere, there are species apparently intermediate 

 between these large genera, and several smaller ones are only 

 separated by characters of little importance. Poa has also been 

 distinguished from Pestuca by the obtuse, always unawned glumes, 

 and by the non-adherence of the grain to the palea. The former 

 character is general, but not absolute ; several species of Poa 

 have acute glumes, and in P. lanuginosa, Poir., they bear a fine 

 point which might almost be termed a very short awn. And as 

 to the grain, though it is usually free, there are several Chilian or 

 Australian species and some Asiatic ones where it is adherent to 

 the palea, as in Festuca, and even in the common Poa pratensis 

 it is often more or less adherent, whilst there are several true 

 Pestucas where it is quite free. 



Most of the widely spread species of this genus are so variable 

 that it would require much more research into specific detail 

 than I can at present bestow upon them to distribute them into 

 natural groups or sections ; and I can only refer to the following 

 as having been proposed as sections or separate genera : — Pseudo- 

 poa, proposed by C. Koch as a section oi Festuca, includes P.per- 

 sica, Poir., and two other temperate-Asiatic species, with very 

 small spikelets and with nearly the habit oi Nephelochloa, to which 

 Grisebach has referred them, but which appear inseparable from 



