Mr. Woods on the Genera of European Grasses. 37 



acute teeth, with an intermediate slender geniculate and twisted dorsal 

 awn. Seed without a furrow and without a crest. 



5. Avena. Glumes nearly equal, 2 or more flowered, herbaceous, with a sca- 



riose margin. Outer palea scariose, nerved, ending in two points, with 

 an intermediate geniculate and twisted dorsal awn. Seed furrowed, and 

 hairy or crested, elliptic-oblong, attached to the inner palea. 



6. Gaudinia. Spiculae many-flowered, in two opposite rows on an alternately 



channelled brittle rachis. Glumes very unequal, the longest (superior) 

 much shorter than the spicula. 



7. Arrhenatherum. Glumes 2-flowered, the lower barren, with a geniculate 



and twisted dorsal awn. Awn of the fertile floret short and straight. 

 Paleee scariose, the outer ribbed and ending in two points. 



8. Holcus. Glumes 2-flowered, the lower perfect, awnless ; the upper barren or 



perfect, with a dorsal awn. Palese without ribs, hardening on the seed. 



9. Danthonia. Glumes 2 — 3-flowered, membranous, as long as the spicula. 



Outer palea quite smooth and coriaceous below, rounded at the back, 

 bifid, with a firm, broad, intermediate point, which sometimes becomes 

 the base of a geniculate awn. 



The difference of habit seems to justify the separation of Deschampsia from 

 Aira. It has usually the more or less perfect indication of a third floret, which 

 is wanting in the latter genus. The straight awn also rising from near the base 

 is never wanting, and such an awn is found in no species of Aira. I am more 

 inclined to rest upon this character than upon the 4 teeth of the paleae, which, 

 it seems to me, are not cut with such precision as to give much confidence in 

 their always occurring in the same number ; and similar teeth are not unfre- 

 quent in A'lrajlexiiosa. Indeed I find hardly any Grass where this part has 

 the firmness and regularity exhibited in the figures of Palisot de Beauvois. I 

 unite Corynephorus and Airopsis to the remaining species of Aika. The first 

 has a distinct and beautiful character in its clubbed awn and the little tuft of 

 hairs at the genicula, but the habit is that of some species of Aira. Airopsis 

 has been separated on its want of an awn, and on the three lobes or teeth 

 which terminate the inner palea. Yet Kunth says, " obsolete triloba," which 

 does not indicate a clear distinction. What he considers as genuine species 



