36 Mr. Woops on the Genera of European Grasses. 
and as long, or nearly as long as the spicula, and this contains, except in 
Lagurus and in Arrhenatherum, two or more perfect florets. With the excep- 
tion of the latter genus, the tendency of this tribe is to perfect its lower florets, 
while the upper ones are frequently imperfect and tabescent. The palez are 
unequal in substance, the outer being much the firmest, frequently strongly 
ribbed, and generally with a scariose margin or extremity. The inner is alto- 
gether scariose, except on the two keeled nerves, permanent, and embracing 
the seed. A jointed and twisted awn rises from the back of the outer palea, 
but this is sometimes wanting. The inflorescence is in a panicle, spreading 
all round, except in Gaudinia, where it is in a spike, the spiculæ being in 
opposite rows on a fragile, alternately channelled rachis. The inequality of 
substance in the paleæ, and the greater firmness of the outer, as compared to 
the glumes, may be added to the marks already pointed out, which distinguish 
these plants from the drundinacee. "They are separated from the Festucaceæ 
chiefly by the nature of the awn, by the stiff hairs at the base of the floret, 
and by the greater comparative length of the glumes. Unfortunately, the stiff 
hairs at the base of the floret do not always exist; nor is the dorsal, genicu- 
late awn always present. The awn or seta among the Festucaceæ is never 
geniculate, although it is somewhat curved and twisted in some species of 
Bromus; but the awn in the Avenacee arises from the substance of the paleæ, 
and never from the union of several nerves as in that genus, while in the other 
genera of Festucaceæ it is evidently a mere continuation of the midrib. 
The genera are: 
l. Aird. Glumes 2-flowered, without any rudiment. 
included. Awn, if any, dorsal, geniculate. 
2. Deschampsia. Glumes keeled, containin 
g (but not including) 2 perfect 
florets, and the rudi : | pP 
WEE: iment of a third more or less developed. Awn dorsal, 
3. Lagurus. Glumes 1-flowered, 
Outer palea nerved, ending in 
late and twisted dorsal awn. 
4. Trisetum. Glumes 2—6-flowered 
; membranous, not exceedi 
ie | » ding the florets. 
pa : riose, without nerves or any distinct keel, ending in two 
Outer palea nerveless, 
Scariose, ending in a long fringed seta! 
two long setze and an intermediate genicu- 
