24 Mr. Woops on the Genera of European Grasses. 
glume and of the outer palea of the abortive floret meet each in a point, 
which in many cases is prolonged into a seta. O. Crusgalli has, I believe, 
always a filmy inner palea to the neutral floret, but it does not appear that 
this is constant through the genus. A comparison of Kunth’s descriptions of 
the genera Panicum and Oplismenus leaves no distinguishing mark between 
them, except the “glume et pale muticæ” of the former, and * pale mu- 
cronate et glume plerumque aristatze" of the latter. A mark of this sort is 
not often to be depended on among Grasses, and with the qualifying adverb 
it seems to be a very slight distinction. This learned author is amazingly 
careless in his divisions, whether of tribes, of genera, or of species, as to 
whether the description contain, or do not contain, a differentia: he seems in 
all cases to trust rather to the general habit of the plant and to his own tact, 
than to any decided or describable character. 
SETARIA. Sir J. E. Smith says, that the bristle-like involucrum is not suf- 
ficient to form a generic character. I am glad to seize anything which sepa- 
rates a group of plants which have a peculiar appearance. The smaller spikes, 
where the whole is compound, have something of a one-sided appearance, but 
I think rather from their position than from their structure. The whole in- 
florescence is, I believe, invariably alike all round. Since there is a marked 
habit, I am not willing to throw this genus back again into Panicum: how far 
it may be rightly separated from Pennisetum I will not venture to decide, but 
I have high authority for keeping them distinct. In the European species 
the leaves are rough and the sheaths smooth, bearded at the mouth. 
I fou Kunth, rather than my own judgement, in placing Lappaco among 
the Paniceæ, but I do not know where else to put it. The outer glume is 
5 but small, and so thin that it is often difficult to detect it. The 
v ee 8 of structure might give some ground 
3 „ = oret; but as the thin valve is towards 
does not support us in ilis view of di ay -o Es WE 
spikes, not quite sessile, on a ss = dx 2 5 = e yes. 
an angle and having a ae a 2 rid mn eee ESE 
. difference in the direction of the 
— ae to ben 1 the appearance of a one-sided raceme. The spiculæ 
stow all round the rachis of these short spikes; there are two or more of them, 
