Mr. Woods on the Genera of European Grasses. 27 



noticed by other botanists, and which I have not been able to find, yet there 

 is a small callus, which perhaps is peculiar to this grass, whose nature I do not 

 well understand. 



PHLEINEiE. 



I separate these from the Phalaridece on the principle explained by Brown, 

 because they have a tendency to produce an interior instead of an exterior 

 floret, and also on account of the thinness and delicacy of the paleae. Where 

 no indication of an interior floret is observable, we are content to notice that 

 there is no symptom of an exterior one, and to judge of the tendency by ana- 

 logy. There is only one perfect floret in a spicula. The glumes are nearly 

 equal, and include the palese. The inflorescence is in a spike-like panicle 

 tiled all round, and this, perhaps, forms the most marked distinction between 

 this tribe and the Agrostidece, although the palese in the latter tribe have usually 

 more consistency. The genera are : 



1. Achnodcm. Glumes boat-shaped, nearly equal, three-ribbed, the lateral 



ones meeting when closed so as to give the glumes a valvular appear- 

 ance, and a spindle-like form to the whole spicula. Palese 2, nerved, 

 filmy, unarmed. 



2. Phleum. Glumes parallel on the midrib, which is prolonged into a seta, 



embracing, and forming an oblong spicula; palese 2, nerved, filmy or 

 scariose, unarmed. 



3. Alopecurus. Glumes membranous. Palea 1, scariose, awned at the back. 



" Styles combined." Sm. 



4. Crypsis. Glumes and palese membranous, of similar substance and length, 

 ;. unarmed. - 



5. Gastridium. Glumes membranous, including, acute, awnless, ventricose at 



the base. Palese scariose or filmy. The outer truncate ; awn dorsal, or 

 none. 



The boundaries of the two genera Phleum and Phalaris have somewhat 

 shifted their position since the time of Linnseus. His character of Phleum is 

 " Calyx truncatus, mucronatus." That of Smith, " Cal. of 2 close parallel 

 pointed valves concealing the corolla of 2 awnless valves." Hooker omits the 

 parallelism of the valves, which, however, is a striking character if understood 



E 2 



