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 gracilescens

HABIT Perennial; caespitose. Rhizomes short. Culms geniculately ascending, or decumbent; 45–60 cm long; woody; rooting from lower nodes. Lateral branches ample. Leaf-sheaths glabrous on surface. Ligule a fringe of hairs. Leaf-blades flat, or conduplicate, or involute; 10–20 cm long; 3–5 mm wide. Leaf-blade surface smooth, or scaberulous; rough adaxially; glabrous, or pilose; sparsely hairy; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; 3–7.5 cm long; 0.5–0.8 cm wide. Primary panicle branches accrescent to a central axis; with lateral stumps on axis. Panicle axis angular; scaberulous; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets sessile; 1 in the cluster. Involucre composed of bristles; cuneate; 10–20 mm long; base obtuse; base villous. Involucral bristles deciduous with the fertile spikelets; numerous; 15–30 in principal whorl; with one conspicuously longer bristle; 14–24 mm long; terete; flexible; ciliate.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; acute; 3.5–4 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate, or ovate; 1–2 mm long; 0.33–0.5 length of spikelet; hyaline; without keels; 0–1 -veined. Lower glume lateral veins absent. Lower glume apex obtuse, or acute. Upper glume lanceolate; 2.5–3 mm long; 0.75 length of spikelet; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute, or acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous; 3–5 -veined; scaberulous; rough above; acute, or acuminate; mucronate. Fertile lemma oblong; 3.5–4 mm long; membranous; without keel; 3–5 -veined. Lemma margins flat. Lemma apex acute. Palea 1 length of lemma; membranous.

FLOWER Lodicules absent. Anthers 3; 2 mm long; anther tip smooth. Styles connate below; 1 of their length connate.

DISTRIBUTION Africa: northeast tropical.

NOTES Paniceae. FTA 1993.

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