.

=Lophopogon tridentatus, _Hack._=

This is a small annual grass with slender, tufted, erect stems varying
in height from 4 to 12 inches.

_Leaf-sheaths_ are glabrous or with scattered hairs. The _ligule_ is a
fringe of close-set long hairs. _Nodes_ are covered with long hairs
below, but nodes nearer the inflorescence are glabrous.

_Leaf-blades_ are very finely linear, acuminate, rigid, erect, glabrous
below, with long hairs on the upper surface to about quarter the length
of the blade and densely hairy near the mouth, and varying in length
from 2 to 6 inches.

The _inflorescence_ consists of usually two closely appressed spikes,
though appearing as one, 1/2 to 3/4 inch long, pilose with ferrugineous
hairs; the peduncle is capillary and enclosed by the upper leaf-sheath.

[Illustration: Fig. 141.--Lophopogon tridentatus.

1. Awnless lower spikelet; 2. a lower sessile and an upper pedicelled
spikelet; 3. the first glume of an awnless lower spikelet; 4. the first
glume of a lower spikelet that is awned; 5. the first, glume of the
upper or pedicelled spikelets; 6, 7 and 9. the second, third and the
fourth glume, respectively, of the upper pedicelled spikelets; 8 and 10.
palea of the third and the fourth glumes; 11. ovary and anthers.]

The _spikelets_ are densely imbricate, binate at each joint, the upper
being shortly pedicelled and the lower sessile or subsessile. The _lower
spikelets_ are 1/5 inch long with a tuft of brownish hairs at the tip of
the callus. The _lower spikelets_ at the very base of the inflorescence
are awnless and contain only two male flowers, whereas those above in
the inflorescence are awned and contain one male flower and one
hermaphrodite or female flower.

There are four _glumes_ in the spikelet. The _first glume_ in the
awnless spikelets is coriaceous, oblong, cuneate, very sparsely hairy or
glabrous, shorter than the second glume, 7-nerved, 5-toothed at the
apex, two teeth being broader and shorter and three sharper and longer.
The _second glume_ is longer than the first, 1/5 inch long,
sub-chartaceous, lanceolate, 3-nerved, 2-fid at the tip and awned or
aristate, margin hyaline and with long brownish hairs on the marginal
nerves. The _third glume_ is hyaline, a little shorter than the second,
lanceolate-linear, tip bifid or irregularly toothed, paleate with two
stamens or rarely empty; the _palea_ is linear, about as long as the
glume, tip irregularly toothed. The _fourth glume_