Rhytachne] XXVIH, GRAMINEA. 139 
apiculate apex; inner glumes hyaline, 2-nerved, slightly shorter 
than the outer, the lower elliptical with a subequal pale and a ¢ 
flower, the upper ovately elliptical, enveloping a shorter pale with 
a ¥ flower. 
Shoots 16 to 20 in. high springing from the charred broad 
markedly striate barren glabrous leaf-sheaths which form a thick 
covering round their base ; culms } line or less in diameter, with 
generally three internodes, the median one clothed for two-thirds its 
length by the narrow leaf-sheath ; leaf-blade on the short barren 
leafy shoots, which spring from the basal involucre of sheaths, 
reaching 14 in. in length, less than 3 line in diameter, of the 
cauline leaves a few inches only. Spikes 23 to 3 in. long; 
rhachis-joints 24 lines ; gl. I. of sessile spikelet 21 lines long, dingy 
purple; glume of ¢ flower scarcely 21 line, pale 2 lines long, 
anthers 1} line; fertile glume subequal, pale 14 line. 
Near the west tropical African R. rottbellioides Desv., which has 
a very similar habit, but is distinguished by its larger, coarser- 
looking, perfectly glabrous, exaristate spikelets. 
Huiuia.—In sandy-clayey thicket-grown pastures between Humpata 
and Nene ; April 1860. No. 2639. 
7. ROTTBELLIA Linn. f.; Benth. & Hook. f. Gen. Pl. iii. 
p. 1129. 
1, R. exaltata Linn. f. Suppl. p. 114 (1781); Hack. Mon. 
Androp. p. 293; Durand & Schinz, Consp. Fl. Afr. v. p. 699. 
Go.tunco ALTO.—Too common in scanty thickets and on edges of 
woods, near Sange, Bango etc., said to be avoided by cattle ; beginning 
of July 1855. Nos. 7251, 7271, 72710. 
CazENGO.—A tall grass 4 to.6 ft. high, beset with stinging hairs. 
Cucula; June 1855. Cou. Carp. 1110. 
The stinging hairs (pili urentes) to which Welwitsch refers, are 
probably the sharp rigid hairs from a tuberculate base which fre- 
quently occur in the leaf sheaths, and are precisely similar to those 
common in Asiatic specimens. The character was sufficiently marked 
to suggest a specific name for what Welwitsch assumed to be a new 
plant. 
2. R. angolensis Rendle sp. nov. 
Perennial from a stout creeping rhizome, glabrous; culms tall 
reedy, clothed with the rather loose papery overlapping leaf- 
sheaths ; ligule membranous, truncate, glabrous; blade tapering 
rapidly above the sheath, long, narrow linear, plicate, ultimately 
setiform ; inflorescence carried above the leaves, main axis strong, 
terete, the spikelike branches few, long, lax, fastigiate, borne 
singly or in pairs on an elongated common axis; rhachis very 
brittle; spikelets in pairs at each node, similar; sessile spikelet 
about half the length of the rhachis-joint or shorter in proportion, 
outer glume separated from the short callus by ashort horizontal 
