nchlets) are often found on the pedicels. In Setaria a few are borne
by the pedicels. The bristles form a regular involucre at the base of a
group of spikelets in Pennisetum, and in Cenchrus these become united at
the base into a mass forming a kind of burr around the spikelets.

KEY TO THE GENERA.

A. Spikelets articulate on their pedicels.

B. Spikelets without involucels.

C. Spikelets dorsally flattened, awnless.

Inflorescence racemed; glumes
three; nerves of second glume
five or less, side nerves curved 1. Paspalum.

Inflorescence digitate; glumes
three with a minute glume;
nerves of second glume five to
seven, straight and prominent 2. Digitaria.

Inflorescence panicled; glumes
three with a thickening at the
base of the spikelet 3. Eriochloa.

Inflorescence racemed or paniculate;
glumes four, first two glumes
unequal 4. Panicum.

Inflorescence panicled, branches of
panicle produced beyond the
uppermost spikelet; glumes four,
the first being minute and hyaline 5. Chamaeraphis.

Spikelets unisexual and dioecious 6. Spinifex.

CC. Spikelets awned.

Glumes four, second glume broadly
fimbriate with hairs; palea of
the third glume short and deeply
cleft, fourth glume awned 7. Axonopus.

BB. Spikelets involucellate 8. Setaria.

AA. Spikelets not jointed but continuous.

Spikelets in involucelled deciduous
fascicles.

Involucre of bristles free 9. Pennisetum.

Involucre of bristles united 10. Cenchrus.

1. Paspalum, _L._

These are annuals or perennials. The spikelets are plano-convex,
orbicular to oblong, obtuse, secund, 2-ranked on the flattened or
triquetrous rachis of the spike-like branches of a raceme, one-flowered
and falling off entire from the very short or obscure pedicels. There
are three glumes, all more or less equal and similar. The first and the
second glumes are membranous, alike and as long as the third, the second
glume is usually epaleate and occasionally with a minute palea. The
third glume is chartaceous to sub-coriaceous and paleate. Lodicules are
two and small. Stamens are three. The styles are slender and distinct
with plumose stigmas exserted at the top of the spikelet. Grain is
tightly enclosed in the third glume and its palea.