462 
CLVII. GRAMINEiE (Stapf). 
[. Digitaria . 
30. D. leptorrhachis, Stapf. Annual, up to 2 ft. high. Culms 
(base not known) erect, slender, smooth, collapsing and sulcate when 
dry, simple at least upwards, uppermost internode long-exserted. 
Leaf-sheaths somewhat loose, thin, striate, sparingly hirsute and 
ciliate or quite glabrous except at the finely hispidly bearded nodes ; 
ligules membranous, truncate or rounded, crenulate, 1 lin. long ; 
blades linear, long-tapering to a fine point, 3-5 in. by 1-2 lin., flat, 
flaccid, pale green, glabrous or with a few spreading tubercle-based 
hairs towards the base, or very loosely and finely pubescent, scaberu- 
lous upwards along the finely cartilaginous margins and on the upper 
side towards the tips, otherwise smooth, midrib very slender, primary 
lateral nerves 2-3 on each side, obscurely raised above. Racemes 
8-15, sessile or bare at the base with traces of arrested spikelets, 
fastigiate on a slender upwards angular common axis (up to over 
2 in. long, but usually much shorter), solitary or pseudoverticillate, 
often bare at the base for a short distance (up to -1- in.), very slender, 
mostly obliquely spreading, straight or slightly arching, about 3 in. 
long ; rhachis filiform, triquetrous, j lin. wide, angles very finely 
marginate, scabrid, internodes about 1 to over 1J lin. long ; pedicels 
2-nate, finely filiform, very unequal, the longer up to 1 lin. long, 
angular, scaberulous. Spikelets loosely appressed- and loosely dis- 
posed, oblong, acute, 1 lin. by J lin., whitish with fine silvery silky 
lines. Lower glume a minute delicate membrane, early breaking 
up ; upper oblong, as long as the spikelet, with a small obtuse hyaline 
tip, inrolled when dry and then apparently acute, very thin, very 
, distinctly 5-nerved with 4 fine lines of hairs (the space inside the 
submarginal nerve glabrous), hairs very delicate with recurved or 
circulate tips, up to J lin. long. Lower floret : valve very thin, 
corresponding in shape and size to the spikelet, finely 7-nerved, nerves 
equidistant with a dense fringe of hairs along the margin and a fine 
but dense line between the 2 inner lateral nerves (of each half), 
hairs as in the upper glume ; valvule and lodicules microscopic. 
Upper floret lanceolate-oblong, acutely acuminate, as long as the 
spikelet, very pale, thinly chartaceons, margins of valve meeting or 
overlapping upwards (when young). Anthers J lin. long. 
Upper Guinea. French Sudan : on dry land near Segu, Lecard, 252 ! 
Good fodder according to Lecard. Very near to D. nigritianci and to D. poly- 
botrya, differing from both in the slightly larger whitish spikelets with fine 
silvery lines formed by more copious and rather longer hairs, from the former 
also in its bearded nodes. The racemes also seem to be less numerous than in 
either of them. 
31. D. polybotrya , Stapf Annual, up to 3 ft. high. Culms 
erect or subgeniculate, somewhat slender, 3-noded, smooth, collapsing 
and deeply sulcate when dry, simple or sparingly branched, uppermost 
internode long-exserted, the others soon bared by the sheaths slipping 
off. Leaf -sheaths rather loose, thin, finely striate, subherbaceous, 
