90 
as to the identity of the plant. Thus the Kikuyu grass will 
have to be known under the name proposed by him, namely, 
Pennisetum clandestinum, Hochst. ex Chiov 
The two most striking features of Pennisetum clandestinum (see 
Figs. 1 and 2o0n p. 91) are its stunted growth and proclivity to the 
formation of very vigorous runners, and the extreme reduction 
of the inflorescence and its inclusion in the top sheath. In 
habit it resembles strong specimens of Cynodon Dactylon to a 
remarkable degree, so much so that barren specimens of both: 
may be all but indistinguishable. The anatomical differences 
are, however, obvious, as will be seen from the cross sections 
shown on p. 91 (Figs. 11 and 12). Grown in good and well- 
watered soil it throws up barren stems up to 30 cm. (according 
to Melle, l.c., even 1 m.) high with elongated internodes (up to 
7 cm.) and long slender blades (up to over 20cm. by 3-4 mm.), 
whilst the flowering shoots seem to remain short (5-6 cm.) even 
under such favourable conditions (Figs. 3 and 4). The reduction 
of the inflorescence (Fig. 5) affects not only the number of spike- 
lets (2-4), but also the involucral bristles which are short, 
the longest not surpassing three-quarters the length of the 
spikelet, delicate and eplumose and have evidently lost their 
function; further, the glumes, the lower of which is quite 
suppressed, whilst the upper is merely a small nerveless or almost 
nerveless scale; the lower floret which is reduced to its valve and 
finally the stamens which are occasionally arrested, the flowers 
becoming thereby functionally female (Figs. 6-10). The valves 
share the relatively great number of nerves (11—14) with those 
of P. longistylum, but they are narrower, longer, thinner and in 
the lower part almost devoid of chlorophyll—no doubt in 
response to their concealed position. The genetic derivation of 
P. clandestinum from P. longistylum is obvious, but the power 
of reversion to its ancestral type seems to have been lost. The 
reduction of the inflorescences to so few spikelets—and of these 
sometimes a portion only fertile—must mean poor seeding, a 
loss amply balanced by the vigour of the vegetative reproduction 
of the grass by runners and stolons. The area of P. clandestinum 
extends from Eritrea to Mt. Elgon and the highland of West 
Usambura. P. longistylum on the other hand is so far ‘only 
known from Northern Abyssinia, and the adjoining parts of the 
Italian colony of Eritrea. | 
The following is a description of the grass :— 
Pennisetum clandestinum, Hochst. ex Chiov. in Annuar. Ist. 
Bot. Roma, viii. 41, t. v. Fig. ii. (1903). A hermaphrodite or 
sometimes unisexual low creeping closely matting perennial with 
creeping rhizome and slender stolons with very short internodes, 
throwing up single or more often fascicled short stout branches, 
the underground portion of which is densely covered with down- 
wards more or less decayed leaf-sheaths. Culms (over-ground 
stems and branches) very short, often hardly raised above the 
ground or growing out into long rooting runners appressed to 
