ME. G. BENTHAM ON GEAMINEiE. 71 



is small and hair-like or sometimes entirely wanting, and proposed 

 a genus Meoschmm, adopted byNees, for the other species in which 

 the awn is more developed. Trinius considered as true Isolimma 

 only those in which the pedicellate spikelet has only a male flower 

 or empty glume, and added those in which that spikelet has two 

 male flowers to his genus Spodiopogon, notwithstanding the dif- 

 ference in inflorescence &c. Ischcemopogon, Griseb., is I. latifolmm, 

 Kunth, and Hologamium, Nees, is I. laxvm, Br., both species 

 with two-flowered pedicellate spikelets, as is also the case in I. 

 insculptum, Hochst., and I. maerostaehyum, A. Kich., from tropical 

 Africa, and probably also in Porsklhl's genus Sehima, of which 

 we have no authentic specimen. I. pectinatim, Trin., I. leersioides, 

 Munro, I. ophiuroides, Munro, with a fourth unpublished species, 

 all from tropical Asia, form a distinct section {Pectinaria), with 

 slender elegant simple spikes, and the larger glume of the sessile 

 spikelets pectinate-ciliate. 



20. TEACHTPOGtON, Nees, as limited by Andersson, and 21. 

 Heteeopogof, Pers., closely resemble each other in their simple 

 spikes with appressed imbricate spikelets and long rigid twisted 

 awns ; but in Trachypogon the sessile spikelet of each pair is male 

 or sterile and unawned, and the pedicellate one fertile and awned, 

 whilst in Seteropogon the sessile one is fertile and awned, and 

 the pedicellate one male or sterile and unawned. Andersson enu- 

 merates eleven species of Trachypogon, one from South Africa, the 

 others from tropical or subtropical America; but several of the latter 

 can scarcely be regarded as more than slight varieties. Of Setero- 

 pogon there are two well-marked species, H. contortus, Eoem. and 

 Schulfc. (S. hirtus, Pers.), now very common in most warm regions 

 and extending to the Mediterranean region and to North America, 

 and H. melanocarpus, Ell. {H. Moylei, Nees, H. acuminatus, Trin., 

 Trachypogon scroMculatus, Nees), which is in North and South 

 America as well as in East India. Besides these, three or four 

 South- African species have been referred to Seteropogon, but are 

 of somewhat doubtful affinity. 



22. Andeopogon, Linn., taking it within the limits assigned to 

 it by Munro, including all the species of the subtribe with spike- 

 like simple branches to the inflorescence, and without the pecu- 

 liarities of the three preceding genera, is still a somewhat poly- 

 morphous genus of perhaps a hundred species, very abundant 

 within the tropics, but well represented also in Europe, temperate 

 Asia, North America, South Africa, and Australia. The fourteen 



