ME. G. BBNTHAM ON GEAMINEiE. 91 



longation of the rhachilla into a bristle or stipes usually, but not 

 always, hairy, and from Agrostis in the larger spikelets, with the 

 palea nearly as long as the glume, and the usually hairy rhachilla. 

 There are, however, a few species where one or another of these 

 characters fail ; and one or two scarcely diifer from Apera except 

 in the habit and in the awn being more decidedly dorsal. Sro- 

 midium, Nees (to which belong Bidymochceta, Steud., and Ohamm- 

 oalamus, Meyer), contains a few Andine Chilian or Australian 

 species, which, with the minute glabrous and perhaps not con- 

 stant continuation of the rhachilla, might almost as well be 

 transferred to Agrostis, but that they have rather the habit of 

 Deyeuxia. Relchela, Steud. {Agrostis sesquivalvis, E. Desv.), 

 Cinnastriom, Pourn. (at least as to Deyeuxia poedformis, Kunth), 

 Deyeuxia mutica, Wedd., and D. Ireviglwmis, Benth., with a few 

 other South- American species, form a little group with a glabrous 

 rhachilla and the awn reduced to a small point. In Achmta, 

 Fourn., two Mexican species, the awn appears to be deficient ; 

 but all the other characters are those of the typical Z>eyeMa;«<e with 

 a hairy rhachilla, to which I would also refer the Agrostis aqui- 

 valvis, Trin., forming Grisebach's section Podagrostis. 



33. Ammophila, Host (Psamma, Beauv,), comprises four spe- 

 cies, two of them widely spread over the northern hemisphere 

 chiefly near the sea, and two confined to North America. They 

 are distinguished from Deyeuxia by their tall habit, their usually 

 dense inflorescence, and especially by their larger paleaceous 

 glumes. 



34. DiOHELACHNE, Endl., two Australian or New-Zealand spe- 

 cies, with a narrow dense panicle, differs from Agrostis and its 

 allies in the flowering glume scarcely smaller than the outer 

 empty ones and often toothed, and in the long dorsal awns giving 

 the inflorescence a fine bristly aspect. 



35. Teisetaeia, Porsk. (Anomalotis, Steud.), is a maritime 

 Syrian and Egyptian plant, very near Uichelachne, but still more 

 bristly, the lateral teeth of the flowering glumes being produced 

 into fine straight awns, whilst the dorsal one is longer and flexuose. 

 Labillardiere and Delile both mention two fertile flowers in the 

 spikelet. I have only been able to find one in several specimens 

 examined, all from Alexandria; possibly they may have consi- 

 dered the rather long continuation of the rhachilla as a second 

 flower. 



36. PENTAPO&oif, Br., is a single Australian species, with four 



