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 yemense

HABIT Perennial; caespitose; clumped densely. Rootstock evident. Rhizomes short, or elongated. Culms erect; 20–40(–100) cm long. Ligule a fringe of hairs. Leaf-blades 1–3 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; oblong; 6–12(–16) cm long. Primary panicle branches accrescent to a central axis; with lateral stumps on axis. Panicle axis with rounded ribs; pubescent, or pilose; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets sessile, or sessile and pedicelled; 1–3 in the cluster; 1 sessile. Involucre composed of bristles; oblong; 20–30 mm long; base bluntly stipitate; base 1.7 mm long; base villous. Involucral bristles deciduous with the fertile spikelets; numerous; in one whorl; with one conspicuously longer bristle; 30–40 mm long; terete; flexible; plumose.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension, or with a barren rhachilla extension. Spikelets lanceolate; dorsally compressed; 8.5–10 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes one the lower absent or obscure, or two; dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate, or orbicular; 0–1 mm long; 0.1 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume lanceolate; 0.33–0.5 length of spikelet; membranous; without keels. Upper glume apex acute.

FLORETS Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous; 7–9 -veined; acuminate. Fertile lemma oblong; 8–9 mm long; coriaceous; much thinner above; without keel; 5–9 -veined. Lemma margins flat. Lemma apex acute.

FLOWER Lodicules absent. Anthers 3.

DISTRIBUTION Africa: northeast tropical. Asia-temperate: Arabia.

NOTES Paniceae. TAC 1997.

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