82 
CLVII. GKAMINEiE (Stapf). 
[. Uhytachne . 
Leaves auricled at the junction of blade and 
sheath ; blades folded without sclerenchy- 
matic bars running right through and en- 
casing the primary bundles 2. B. rottboellioides. 
Leaves not auricled ; blades subterete, deeply 
channelled, with sclerenchymatic bars 
running right through and encasing the 
primary bundles 3. B. benguehensis. 
Raceme rather tough. Lower glume obtuse, very 
obscurely muricate, 1|— 2 lin. long 4. B. Mannii. 
Annual; culms single or if tufted all flowering, not asso- 
ciated with purely leafy shoots. 
Lower glume transversely rugose ; pedicels with a 
terminal pair of unequal bristles 5. B. triaristata. 
Lower glume slightly tubercled or rugose near the 
base ; pedicels with a single bristle ... . . . 6. B. gracilis. 
1. R. robusta, Stapf. Perennial, compactly csespitose. Culms 
and innovations surrounded by the dried-up firm bases of tlie leaf- 
sheaths, 2-4 ft. high, 2-3-noded, erect, simple, smooth, glabrous or 
softly hairy, terete. Leaf-sheaths tight, mostly longer than the 
internodes, but often their upper parts slipping off the culms, 
terete, usually softly hairy, whitish pubescent at the nodes ; ligules 
membranous, truncate, 1 \ lin. long, scarious, ciliate, reddish ; blades 
linear, long-attenuated towards both ends, with long setaceous tips, 
up to over 1 ft. long and 4-5 lin. wide, firm, drying reddish, usually 
more or less hairy, particularly near the base, or almost glabrous 
in the upper parts, midrib slender, prominent below, whitish, lateral 
nerves fine, numerous, margins scabrid. Raceme spike-like, cylindric, 
over ^ ft. long, slightly over 1 lin. in diam., erect, stiff, brownish- 
or reddish-green, pubescent at the nodes ; joints linear, 4|-5 lin. 
long, somewhat cupular at the top, convex on the back, very slightly 
concave on the inner face, quite hollow, softly ciliate along both 
angles, otherwise glabrous and smooth ; pedicels somewhat shorter, 
narrowly linear and slightly tapering upwards, dorsally very much 
compressed, with a few prominent nerves, angles softly ciliate, 
almost contiguous with the joint. Sessile spikelet linear-lanceolate, 
almost as long as the joint, with a very obscure annuliform pubescent 
callus. Glumes equal ; the lower subacute to acute, coriaceous, 
rounded on the scaberulous back, keeled, very scabrid above, 
intracarinal nerves 4-5, green and distinct seen from within, in- 
visible from without ; upper glume chartaceous, boat-shaped, 
linear in profile, very acute, keel asperulous above, lateral nerves 
2 on each side close to the upwards ciliolate margin. Florets sub- 
equal. Lower floret $ : valve almost as long as the glumes, lanceo- 
late, acute, subhyaline, finely scaberulous, 2-nerved, ciliolate, with 
a valvule of equal length and similar structure, but 2-nerved and 
almost eciliate. Upper floret £ : valve lanceolate, acute, 3-nerved, 
ciliolate, its valvule of the same length, narrowly lanceolate, 
