Rhytachne] xxviii. graminE/E. 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 bi-oad 

 markedly striate barren glabrous leaf-sheaths which form a thick 

 covering round their base ; culms I 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 .V line in diameter, of the 

 cauline leaves a few inches only. Spikes 2tV to 3 in. long; 

 rhachis- joints '11 lines ; gl. I. of sessile spikelet 2|- lines long, dingy 

 purple ; glume of S flower scarcely 2 ~- line, pale 2 lines long, 

 anthers 1^ line ; fertile glume subequal, pale 1 .V line. 



Near the west tropical African R. rotthaMoides Desv., which has 

 a very similar habit, but is distinguished by its larger, coarser- 

 looking, perfectly glabrous, exaristate spikelets. 



HuiLLA. — In sandy-clayey thicket-grown pastures between Humpata 

 and Nene ; April 1860. iS^o. 2639. 



7. ROTTBGELLIA Linn. f. ; Benth. & Hook. f. Gen. PI. iii. 

 p. 1129. 



1. R. exaltata Linn. f. Suppl. p. 114 (1781); Hack. Mon. 

 Androp. p. 293 ; Durand & Schinz, Oonsp. Fl. Afr. v. p. G99. 



GoLUN(;() 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, 72716. 



Cazengo. — A tall grass 4 to (J ft. high, beset with stinging hairs. 

 Cucula ; June 1855. Cou.. Cakp. 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 ci-eeping 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 cai-ried 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 a short horizontal 



