Trachypogon.] clvii. graminea; (Stapf). 
401 
spikelet. Fertile (upper) spikelets more or less terete, avvned ; 
callus acute to very pungent, densely bearded. Glumes equal or 
subequal ; the lower firmly chartaceous to coriaceous, sub- 
convolute, finely 2-keeled upwards, the indexed margins very 
narrow or reduced to a mere rim, nerves 5-9 in addition to the keel- 
nerves, mostly obscure except in transmitted light, more or less 
connected by transverse veins in the upper part ; upper thinner, 
3-nerved, grooved on either side of the rounded keel. Valve of 
lower floret hyaline, 2-nerved, ciliate or ciliolate upwards, of upper 
floret stipitiform, hyaline and -3-nerved at the base, cartilaginous 
upwards and passing into a flexuous or geniculate awn. Valvule 
very small, hyaline or 0. Lodicules 2, small, glabrous. Stamens 3. 
Stigmas laterally exserted ; styles terminal. Grain terete ; embryo 
about half the length of the grain. Male or neuter (lower) spikelets 
dorsally flattened (particularly the lower of a raceme) or more or 
less terete, awnless ; callus 0. Glume and valve of the lower 
floret similar to those of the fertile spikelets. Valve of the upper 
floret narrow, hyaline, entire or 2-toothed, with or without a 
minute mucro, rarely produced into a short bristle. Stamens 3. 
Pistil, if present, rudimentary. — Perennial (very rarely annual ?), 
densely csespitose grasses with more or less slender wiry culms 
conspicuously bearded below the nodes ; the beards appressed, 
covering the constricted nodes ; leaf -blades narrow, frequently 
convolute. 
Species 9 or 10, all closely allied, ranging into South Africa, Madagascar, and 
most of the hotter regions of America. 
Culms very slender, geniculate -ascending, branched, 
1^ ft. high ; blades about 5 in. by l-l|din., with stiff 
tubercle -based hairs ; annual (?) ... ... ... 1 . T. Ledermannii. 
Culms more robust, erect (rarely geniculate) from a dense 
tuft, simple ; distinctly perennial. 
> Leaf-blades filiform-convolute or the lower unrolled and 
flat when dying off and then up to slightly over 
1|- lin. wide, the longest much attenuated towards 
the base and there semiterete or channelled in cross 
section. 
Lower glume of subsessile spikelets (particularly of 
lower pairs) loosely involute, dorsally much flat- 
tened, up to over 1 lin. wide, distinctly and often 
broadly winged from the keels towards the tips, 
wings reddish ^ stipules , very short, of the culm- 
Jeaves up to 1^ lin. long ... ... ... ... 2. T , Thollonii. 
Lower glume of subsessile spikelets more involute (to 
almost cylindric), quite wingless, keels very 
finely marginate and scabrid upwards. 
Awn 24 to almost 3 in. long, spirals of column very 
steep and closing up so tightly as to make the 
column appear solid ; blades (at least the lower) 
at length unrolling and flat, up to 14 (rarely 
almost 2) lin. wide ; ligules of culm-leaves often 
elongated 3. T. plumosus. 
El. TROP. APR. VOL. IX. PT. 3. 2 D 
