Rhytachne.'] 
CLVII. GRAMINE^ (Stapf). 
85 
4. R. Mannii, Stapf. Perennial, densely tufted; innovations 
intra vaginal, surrounded by the remains of the slender basal leaf- 
sheaths, up to over 1 ft. high. Culms very slender, 2-3-noded, 
slightly compressed, glabrous and smooth. Leaf-sheaths tight, 
finely striate, glabrous and smooth ; ligules very short, membranous, 
ciliolate, obscurely auriculate ; blades complicate, setaceous, up to 
over 1 foot long, J lin. wide when folded, with 2-3 primary faint 
nerves, smooth and glabrous below, very minutely puberulous 
above. Racemes solitary, very slender, rather tough, about 2-3 in. 
long, flexuous, glabrous, pale greenish ; joints linear, up to 1J lin. 
long, slightly clavate and hollow above, shallowly concave on the 
inner face, more or less rounded on the back, with few slightly 
prominent nerves, smooth, disarticulating horizontally ; pedicels 
linear, clavate, slightly curved, contiguous with and about as long 
as the joints, much compressed, ciliolate on the outer angle, with a 
more or less distinct middle nerve. Sessile spikelet oblong, obtuse, 
1 J lin. long, with an obscure callus, dull straw-coloured. Lower 
glume subcoriaceous, obtuse, with few and short transverse rugse 
or little knobs, mainly on the sides of the lower half or right across 
the base, rarely almost smooth, margins ciliolate neaT the apex, 
nerves about 7, very faint, sometimes very slightly prominent 
above on the back ; upper glume membranous, linear in profile, 
acute, muticous, 3-nerved. Lower floret £ : valve oblong, obtuse, 
slightly shorter than the glumes, hyaline, faintly 2-nerved, with a 
similar 2-nerved valvule. Upper floret : valve oblong, subobtuse, 
hyaline, f lin. long, faintly 1-nerved and minutely ciliolate, with a 
valvule J lin. long. Anthers under 1 lin. long. Stigmas J lin. long, 
purple. Pedicelled spikelet completely suppressed, or indicated by 
a minute point. — R. rottboellioides, Franeh. Contr. FI. Congo Fran§. 
12 partly. 
Lower Guinea. Spanish Gaboon : Corisco Island, in meadows, Mann, 1886 ! 
French Congo : Brazzaville, Thollon ! 
There are two specimens attributed to Thollon and named R. rottboellioides 
at Kew, one with obtuse and almost smooth lower glumes and the other with 
acute and transversely rugose lower glumes, both being extremely similar in 
general appearance. One is numbered 73 and this is referred, above, to R. 
rottboellioides, whilst the other, without a number, is accounted for under 
R. Mannii. ^ 
5. R. triarista^a* Stapf. Annual. Culms fascicled in small tufts, 
up to 1J ft. high, ' slender, simple or with a few erect flowering 
branches from the lower nodes, 3-4-noded, terete, glabrous like the 
whole plant. Leaf-sheaths tight, fairly firm, striate ; ligules very 
short, membranous, ciliolate, forming small auricles at the mouth 
of the sheath ; blades convolute, setaceous or very narrowly linear, 
J to over 1 lin. wide when flattened out, glabrous and smooth below, 
very minutely puberulous (with some long fine hairs intermixed) 
above, primary nerves 2 on each side, raised below. Racemes 
