82 MR. G. BENTHAM ON GRAMINEX. 
the lowest glume, leaving, as the spikelet falls away,a slight 
dilatation or callosity at the apex of the persistent portion. 
Sometimes it is not easily observed at the time of flowering, but 
becomes more marked as the fruit ripens. A similar marked 
articulation has not hitherto been observed in Poacese, except in 
Fingerhuthia. There are also a very few cases where the lowest 
glumes are reduced to slight callosities, or are so rudimentary as 
to render it difficult to say whether the articulation is in the 
pedicel or in the rhachilla. In the Cenchrus group of the tribe 
Paniceæ, in the subtribe Anthephoree of Zoysiew, and in some 
Andropogonee, the articulation is not under each spikelet, but 
under a little cluster of two or more spikelets ; and in Maydez it 
is the rhachis of the spike which disarticulates under each female 
spikelet. In Graminee generally, however, the articulation, 
whether of the rhachis, of the pedicel, or of the rhachilla, is 
usually under the fertile spikelets or flowers only; under the 
males it is apt to be very obscure or quite obsolete. 
The fertile flower is above spoken of as only apparently ter- 
minal, because the presence of the palea and a slight obliquity 
tend to show that the floral axis is not really the continuation of 
the rhachilla, but, as in Poacee, a secondary or axillary branch. 
Doell says, indeed, that a continuation of the rhachilla behind 
the palea has been observed in a species of Panicum ; but I have 
never succeeded in meeting with it in any Panicacew. In the 
tribe Oryze&, where there is no two-nerved palea, it may still re- 
main a matter of doubt whether the floral axis is oris not distinct 
from the rhachilla—whether the uppermost scale is a glume on 
the rhachilla or a palea at the base of the floral axis. The pre- 
sence or absence of a central nerve is not an absolute test ; for it 
is occasionally, though very rarely, absent in the lower glumes. 
Panicacee have never more than four glumes, the uppermost 
one ° usually enclosing or subtending the fertile flower, though in 
some Andropogone& it is excessively reduced or even quite 
obsolete or rudimentary. The next under it may be empty like 
the lower ones, or may enclose a palea, a rudimentary flower, or 
a perfect male flower, and in Beckmannia, and a very few species 
or individuals of Setaria and Panicum, this lower flower may be 
hermaphrodite, but usually, if not always, sterile. The two lower 
glumes when present are always empty. Where the spikelets 
are unisexual, the females have only the single terminal flower, 
the males most frequently two flowers, both with perfect 
stamens. 
