76 ME. a. BENTHAM ON GEAMINBiE. 



one-nerved, but otkerwise the character of Phalarideaj is constant. 

 They comprise the following six genera : — 



1. Ehehaeta, Thunb. {Trochera, L. 0. Eich.), has twenty-four 

 species, of which two are from New Zealand, two from the Mascarene 

 Islands, and all the rest from South Africa. In them the glumes 

 of the second pair are the largest, empty and usually awned, and 

 the fertile flower has six stamens. 2. Miceoij3N"A, Br., including 

 Biplax, Hook, f , has five Australian or New-Zealand species, 

 differing from EhrJiarta only in the number of stamens reduced 

 to four or two. 3. Teteaeehejsta, Br., four Australian species, 

 with four stamens to the flower as in MicrolcBna, but the glumes 

 are in less regular pairs, all unawned, and the fourth (one of the 

 second pair) alone the largest. The panicle is also almost always 

 contracted into a spike, not, however, so dense and cylindrical as 

 in the following two genera. 



4. Phalaets, Linn., has nine or ten extratropical species, 

 chiefly from the Mediterranean region, but also extending to 

 North and South America. In this genus it is the lowest two 

 persistent empty glumes that are the largest, usually very flat, 

 and often winged on the keel, the second pair (like the lowest in 

 Oryza) very narrow, sometimes reduced to small bristles, those 

 of the upper pair thin and hyaline ; and sometimes in both of 

 them, but almost always in the uppermost one, the central nerve 

 is very faint or quite obsolete, a character adduced as an argu- 

 ment that this upper one is a two-nerved palea on the floral axis, 

 and not a glume on the main rhachilla. The two nerves are, 

 however, very faint, and the central keel is usually marked by a 

 line of hairs on the outside, and the question remains a moot one. 

 In the majority of species the panicle is contracted into a dense 

 globular or cylindrical head ; but in P. arundinacea, Linn,, a stout 

 taU species, forming the geoMsJOigr aphis, Ivm. {Baldingera,QfS&Tin., 

 Meg., and Schrad., TypJioides, Mcenoh), the inflorescence, though 

 still very dense, is more or less branched or interrupted. This 

 genus has also been supposed to be distinguished by the want of 

 the broad wings of the outer glumes, so conspicuous in the com- 

 mon P. canariensis ; but these wings are very narrow in P. para- 

 doxa, Lian., and entirely disappear in P. intermedia, Bosc (P. 

 aHimcajjo, Ell.), leaving no available character to separate Z)*^?-^^^'* 

 generically. 



5. Ahthoxahthtjm, Linn., has four or five European species, 

 of which one is now widely spread over various regions of the 



