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 pirottae

HABIT Perennial. Culms geniculately ascending; 150–300 cm long; 3–9 mm diam. Lateral branches fastigiate. Ligule a fringe of hairs. Leaf-blades lanceolate; 7–20 cm long; 6–20 mm wide. Leaf-blade surface scaberulous; rough abaxially. Leaf-blade margins scaberulous.

INFLORESCENCE Synflorescence compound; fastigiate (bunches of 3–12 inflorescences). Inflorescence a panicle; terminal and axillary.

Panicle spiciform; linear; 0.8–2.5 cm long. Primary panicle branches accrescent to a central axis; with lateral stumps on axis. Panicle axis scaberulous; glabrous.

Spikelets subtended by an involucre. Fertile spikelets sessile; 1 in the cluster. Involucre composed of bristles; base obtuse. Involucral bristles deciduous with the fertile spikelets; in one whorl; 1 in principal whorl; 7–9 mm long; terete; flexible; glabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; acute; 3–3.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate.

GLUMES Glumes similar; shorter than spikelet; thinner than fertile lemma. Lower glume oblate; 0.5–0.75 mm long; 0.75 length of upper glume; 0.15–0.2 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume ovate; 0.75–1 mm long; 0.25–0.33 length of spikelet; hyaline; without keels; 0 -veined. Upper glume primary vein absent. Upper glume lateral veins absent. Upper glume apex obtuse.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 1 length of spikelet; membranous; 5 -veined; scaberulous; acute. Fertile lemma elliptic; 3–3.5 mm long; cartilaginous; without keel; 5 -veined. Lemma surface smooth, or scaberulous. Lemma margins flat. Lemma apex acute. Palea cartilaginous.

FLOWER Anthers 3; 2 mm long.

DISTRIBUTION Africa: northeast tropical.

NOTES Paniceae. FTA 1993.

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