Fig. 115.—Pennisetum cenchroides.
Pennisetum cenchroides, Rich.
This grass is a perennial. It consists of aerial branches and underground rhizomiferous stems, bearing thick fibrous roots and numerous buds covered by scarious sheaths. The aerial branches are tufted, erect or decumbent and geniculately ascending when in flower, much branched from the base, 6 to 24 inches long (under favourable conditions may reach even 3 to 4 feet in length).
The leaf-sheath is slightly compressed, keeled, with scattered long hairs outside, shorter than the internodes. The ligule is a short thin membrane fringed with hairs.
The leaf-blade is linear, tapering to a very fine point 1-1/2 to 6 inches (sometimes 18 to 20 inches) by 1/8 to 1/4 inch scaberulous with fine long tubercle-based deciduous hairs scattered above, and the lower surface glabrous or with a few distantly scattered fine long hairs, broad at the base and constricted at the point of junction with the sheath.
The inflorescence is a raceme of spikes, varying from 1-1/2 to 3-1/2 inches, with the spikes mostly densely arranged, though occasionally distant and not close-set, on a long; slender, puberulous or scaberulous peduncle; rachis is flexuous, flattened, grooved and scaberulous. The spikes have involucels, consisting of two series of bristles, the outer bristles are horizontal or reflexed, numerous, fine, filiform, scabrid and purple above, shorter or longer than the spikelets; the inner bristles are two to three times longer than the spikelets, flattened and thickened at the base with a strong green nerve, ciliated with long tubercle-based hairs; one of the bristles is longer than the others and the bases of the bristles are connate at the very base into a ring; the upper portion of the bristles are filiform, scabrid and purple, the lower flattened portion being pale.