GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Pennisetum trisetum

HABIT Perennial. Culms 100–300 cm long. Ligule a fringe of hairs. Leaf-blades 15–45 cm long; 3–18 mm wide; glaucous.

INFLORESCENCE Synflorescence compound; scanty. Inflorescence a panicle; terminal and axillary.

Panicle spiciform; linear; 2–7 cm long; 0.4 cm wide. Primary panicle branches accrescent to a central axis; with lateral stumps on axis. Panicle axis with rounded ribs; scaberulous; glabrous, or pubescent; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets sessile; 1 in the cluster. Involucre composed of bristles; oblong; 0.5–3 mm long; base truncate. Involucral bristles deciduous with the fertile spikelets; few; 2–6(–15) in principal whorl; with one conspicuously longer bristle; 3–15 mm long; terete; flexible; glabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 2.8–4(–5) mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; shorter than spikelet; thinner than fertile lemma. Lower glume oblong; 0.5 mm long; 0.1–0.2 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex truncate, or obtuse, or acute. Upper glume elliptic; 0.8–1.5 mm long; 0.33 length of spikelet; membranous; without keels; 1–3 -veined. Upper glume apex obtuse, or acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 1 length of spikelet; membranous; 5–7 -veined; scaberulous; acute. Fertile lemma elliptic; 2.8–5 mm long; membranous; without keel; 5 -veined. Lemma surface scaberulous. Lemma margins flat. Lemma apex acute. Palea membranous.

FLOWER Lodicules absent. Anthers 3; anther tip smooth.

DISTRIBUTION Africa: west-central tropical, northeast tropical, east tropical, and southern tropical.

NOTES Paniceae. FTEA.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.