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 advena

HABIT Perennial; caespitose. Culms erect; 100–150 cm long. Culm-nodes glabrous. Lateral branches lacking, or sparse. Leaf-sheaths glabrous on surface; outer margin hairy. Ligule a ciliolate membrane; 0.5–0.8 mm long. Leaf-blades 33–52 cm long; 6–11 mm wide; purple. Leaf-blade margins scabrous; ciliate; hairy at base.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; nodding; flexuous; 23–32 cm long; 3–5.8 cm wide. Primary panicle branches accrescent to a central axis; with sessile scars on axis. Panicle axis with rounded ribs; pubescent; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets sessile and pedicelled; 1–3 in the cluster. Involucre composed of bristles; 11.7–25 mm long; base obtuse; base 0.5–1.1 mm long. Involucral bristles deciduous with the fertile spikelets; numerous; with an outer whorl of thinner bristles; 45–80 in principal whorl; inner bristles longer than outer; with one conspicuously longer bristle; 21.3–33.6 mm long; terete; flexible; ciliate.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5.3–6.5 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume oblong; 0.5–1 mm long; 0.1–0.2 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume oblong; 1.9–3.6 mm long; 0.5 length of spikelet; membranous; without keels; 0–1 -veined. Upper glume primary vein absent, or distinct. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret elliptic; 4.7–6.1 mm long; 0.9 length of spikelet; chartaceous; 5 -veined; acuminate. Palea of lower sterile floret 4.5–5 mm long. Fertile lemma lanceolate; 5.2–6.1 mm long; chartaceous; without keel. Lemma margins flat. Lemma apex acuminate. Palea 4.7–5.6 mm long; chartaceous; 2 -veined.

FLOWER Anthers 3; 2.5–2.7 mm long.

DISTRIBUTION North America: northeast USA and south-central USA.

NOTES Paniceae. Wipff & Veldcamp 2004.

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