ME. a. BENTHAM OV GBAMINE^. 109 



and Festuca are connected by a number of smaller ones, wbich. 

 are more variously associated together or separated by European 

 botanists than almost any others of the Order. As a whole, 

 Testucese should include all the Poacess with two or more perfect 

 flowers to the spikelet, which have neither the peculiar inflores- 

 cence of Chloridese or of Hordeese, nor the dorsal or twisted awn of 

 AvenesB, nor the peculiar habit of Bambusese. But we have seen 

 that there are a few species where the awn is wanting, but which 

 must yet be left in Avenege ; we shall find that in Diplachne, Oreo- 

 cJiloa, and even in Festuca itself, there is occasionally an inflores- 

 cence very nearly that of Chlorideae ; and with regard to Bambusese, 

 distinct as is the habit and foliage of the great mass of genera, yet 

 it is exceptional in Planotia, and in the subtribe Centotheceae of 

 Festucese there is some approach to that of the Bambusese. The 

 subdivisions proposed of the Order into subordinate groups 

 have been so various, and often on such plausible (though some- 

 times contradictory) grounds, that it is not without hesitation 

 that I have selected for adoption the following eight subtribes : — 

 Subtribe 1. Pa^popTiorecB, has often been raised to the rank of 

 a substantive tribe, but with various limits ; and it really is only 

 distinguished from Triodiese by the more nnmerous teeth, lobes, 

 or awns of the flowering glumes. There are- five well-established 

 genera, requiring little comment. 



1. PoMMEHErLLA, Linn, f., is a single East-Indian annual, 

 with short spikes almost enclosed in the upper leaf-sheaths, and 

 remarkable for the presence of two empty glumes between the 

 ordinary lower pair and the flowering ones, as in Ctenium, Fre- 

 mochloa, BrylMnia, and Uniola. 



2. Pappophoeitm, Schreb., has nearly twenty species from the 

 warmer regions of both the New and the Old "World, distributed 

 in two sections, regarded by some as distinct genera : — Poly- 

 rhaphis, Trin., a few American species in which the flowering 

 glume has thirteen to twenty-three very unequal awns ; and 

 Frmewpogon, Desv., chiefly, but not exclusively, from the Old 

 "World, in which the flowering glume has nine awns, all nearly 

 equal, or five of them rather external and slightly different from 

 the four inner ones. 



3. CoTTEA, Kunth, is a single tropical American species, 

 differing from PappopJiorum in the looser panicle, and in the 

 flowers usually more than two, instead of only one or two, ia 

 each spikelet. 



LINH. JOUEN. — BOTANT, VOL. XIX. K 



