54 MR. G. BENTHAM ON GRAMINEZ.,. 
leave it uncertain whether it is a glume or a palea—that is, whether 
it be attached to the end of the rhaehilla or primary axis of the 
spikelet, or to a secondary or floral axis reduced to a mere point. 
There are theoretical reasons in favour of both explanations, and 
actual observation is insufficient for determining the point. The 
first of these views has appeared to me the most plausible; and I 
have aecordingly in my diagnoses and descriptions treated the 
seale in question as the flowering glume, and considered the 
palea as deficient, as it certainly is in some Andropogonee and 
Agrostew. In this view the technical distinction between the 
two tribes would be, that the Oryze& have 2, 4, or rarely 3 glumes, 
all above the articulation of the pedicel, and the Phalaree 4, 6, or 
rarely 5 glumes, the lowest pair persistent below the articulation 
of the rbachilla. Oryzez thus characterized may be thought as a 
whole to be a rather artificial tribe; but they are divisible into 
two much more natural groups or subtribes— Zizaniec, tropical or 
American genera, often semiaquatie plants, with a loose in- 
florescence and stamens often, but not always, more than three ; 
and Alopecuree, European or temperate Asiatic or African genera, 
with a dense spike-like inflorescence and stamens never more than 
three. 
Zizanies includes the following eight genera :— 
1. Hyprocutoa, Beauv., a single species from Carolina, and 
there apparently rare, differing from Zizania chiefly in the inflo- 
rescence reduced to few-flowered spikes, of which the terminal 
one male and pedunculate, the lower ones female and sessile in 
the axils. 
2. Zızanıa, Linn., comprises two species, or according to others 
two genera, each with two or more species. Asa whole, the genus 
is a natural one, well characterized by the unisexual spikelets in 
an androgynous panicle, each one with only two glumes and the 
males with six stamens. The typical Z. aquatica, Linn. (Hydro- 
pyrum, Link), has the lower part of the panicle more spreading 
and male, and the upper part narrow and female; it is widely 
spread over North America, and includes the East-Russian and 
Japanese Z. latifolia, which is absolutely identical with some 
North-American specimens. The other species, Z. miliacea, 
Kunth (Zizaniopsis, Doell), has the male and female spikelets 
more mixed in the panicle, the awns shorter, the styles more 
connate, and the grain broader—characters which appear to me 
quite insufficient for generic distinction. It isa North-American 
