Mr. Woops on the Genera of European Grasses, 39 
The spicule of Avena are said to be 3 or more flowered, but we cannot 
depend on this character, since À, sativa and 4. orientalis have only 2; 
and this is sometimes the case with. 4. fatua, A. hirtula, À. amethystina, 
A. brevis, and A. alba, among the Grasses of Europe: we must, therefore, 
chiefly rely upon the furrowed and crested seed to distinguish it from Aira as 
well as from Trisetum. The awn is said to be from the base of the palea in 
Aira, and from the back in Avena, and the former has a shining panicle, but 
there are exceptions both ways to each of these circumstances. 
GAUDINIA is readily distinguished by its spiked florets and unequal glumes, 
and I think there is no danger of its being referred to any other tribe. The 
geniculate dorsal awn is not to be found among the Hordeaceæ or Rottboelli- 
acec. 
ARRHENATHERUM and Horcus are sufficiently marked by the characters 
above given. "The habit of the plant obliges me to place here the first of these 
genera in spite of the outer imperfect floret. It cannot be confounded with 
any of the Paniceæ or Phalarideæ. The membranous and strongly-ribbed 
paleæ and geniculate dorsal awn keep it quite distinct from these families. 
Dantuonta decumbens has been considered as a Poa and as a Festuca, and it 
might seem, therefore, probably to belong to the Festucaceæ, but I think 
Kunth has done well in placing it here. I am in this principally guided by 
the large membranous glumes, and by its close affinity to D. provincialis, 
from which it differs almost in nothing but in the want of the twisted upper 
part of the awn. Without pretending to decide whether Triodia, of which I 
know nothing, be really a distinct genus, I cannot agree with those who would 
separate these two species. 
FESTUCACEZ. 
This is on the whole a very distinct tribe, although closely allied by some 
of its genera to the Avenacee on the one hand, and to the Hordeacee on the 
other. The spiculz are scattered, many-flowered. The glumes are unequal, 
shorter than the spicula, generally thinner than the outer palea, notes: of a 
thicker or firmer substance. The outer palea is usually more or lese distinctly 
nerved or ribbed, herbaceous or membranous, not coriaceous while the -— 
is in flower, but in some species hardening on the seed; while in others the 
inner becomes attached to the seed without alteration. They generally have 
