Rhjtachne .] clvii. gramine.® (Stapf). 87 
1 f lin. long, rounded on the back, slightly concave on the inner face, 
slightly rough, disarticulating horizontally, the scar surrounded by 
a ciliolate rim ; pedicels linear-lanceolate, flattened, contiguous 
with the joint, faintly nerved. Sessile spikelet lanceolate-oblong, 
with a small annular callus, If lin. long, without awns, dull reddish- 
brown. Lower glume chartaceous, acute, transversely and obscurely 
rugose below the middle, the rugae often broken up into tubercles, 
about 9-nerved, with the nerves faintly raised above, keels rigidly 
ciliolate above the middle, continued into equal or unequal bristles, 
lf-2 lin. long ; upper glume equalling the lower, subhyaline, lanceo- 
late, with a fine terminal bristle, If lin. long, 3-nerved. Lower 
floret c£ : valve lanceolate, hyaline, 1 lin. long, faintly 2-nerved, 
with a smaller valvule. Upper floret : valve lanceolate, acute, 
hyaline, about § lin. long, 1 -nerved, with a very much smaller 
valvule. Anthers purple, f lin. long. Pedicelled spikelet reduced 
to a bristle about If lin. long. 
Upper Guinea. French Guinea : Kouroussa, Pobeguin, 494 ! Timbo, 
Pobeguin, 1764 ! 1766 ! 1767 ! 17906 ! 
I , 
22. IMPERATA, Cyr. ; Benth. et Hook. f. Gen. PI. iii. 1125. 
Spikelets all alike, generally 2-nate (one short-, the other long- 
pedicelled) on the continuous branches (racemes) of a spike-like or 
narrowly thyrsiform panicle, disarticulating from the pedicels. 
Florets 2 ; the lower reduced to an empty valve (very rarely $ ?). 
Glumes subequal, membranous, 3-9-nerved, rarely nerveless, 
enveloped by very long silky hairs from the obscure callus and the 
lower portion of both glumes. Valve of the lower floret generally 
much smaller than the glumes, hyaline ; of upper floret still smaller, 
} hyaline, awnless, rarely 0. Valvule broad, hyaline, nerveless. 
Lodicles 0. Stamens 1-2. Styles connate below ; stigmas linear, 
exserted from the top of the spikelet. Grain oblong ; embryo half 
the length of the grain or more. — Perennial ; basal leaves crowded 
and, like those of the innovation shoots, long ; panicle silvery-silky. 
Species 5 or 6, mostly closely allied, in the warm regions of both hemispheres. 
1. I. cylindrica, Beauv. Agrost. 165, t. v. fig. 1, Explan, planch . 5. 
Culms lf-4 ft. long, erect, 3-4-noded, glabrous. Leaf -sheaths 
rather loose, glabrous, the lowest at length usually breaking up into 
fibres ; ligules membranous, short, hairy ; blades linear, from a 
very narrow base, tapering to an acute point, the lowest f-1 ft. by 
1-2 lin., the upper very short, rigid, usually convolute, glabrous or 
beardeji at the base, smooth below, margins scabrid, midrib stout. 
Panicle spike-like, 2-8 in. long, cylindric, very dense ; branches 
and branchlets very numerous, crowded, appressed ; pedicels fine 
with clavate tips, f-lf lin. long, with long fine hairs below. Spike- 
lets about 2f lin. long, pale or purplish, enveloped by hairs 5-6 lin. 
