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 complanatum

HABIT Perennial. Rhizomes elongated. Culms geniculately ascending, or decumbent; 75–200 cm long; 2–3 mm diam.; without nodal roots, or rooting from lower nodes. Culm-nodes glabrous, or pubescent. Lateral branches ample; arising from lower culm and mid culm. Leaf-sheaths longer than adjacent culm internode; outer margin glabrous, or hairy. Ligule a fringe of hairs; 1–1.6 mm long. Leaf-blades flat, or conduplicate; 15–55 cm long; 3–7 mm wide. Leaf-blade surface scabrous; glabrous; hairless except near base.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear, or oblong; 8–12 cm long; 0.7–1 cm wide. Primary panicle branches accrescent to a central axis; with lateral stumps on axis. Panicle axis angular; scabrous; with scattered hairs; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets sessile; 1 in the cluster. Involucre composed of bristles; oblong; 8–12 mm long; base obtuse; base 0.7 mm long. Involucral bristles deciduous with the fertile spikelets; numerous; with an outer whorl of thinner bristles; inner bristles longer than outer; with one conspicuously longer bristle; 10–15 mm long; terete; flexible; glabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; acute; 5–6 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes shorter than spikelet; thinner than fertile lemma. Lower glume ovate, or orbicular; 0.33 length of spikelet; 0–1 -veined. Lower glume lateral veins absent. Upper glume ovate; 3.8–4.6 mm long; 0.75 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret ovate; 1 length of spikelet; membranous; 7 -veined; acute. Fertile lemma ovate; 4.4–5.7 mm long; chartaceous; without keel; 5 -veined. Lemma margins flat. Lemma apex acute. Palea chartaceous.

FLOWER Lodicules absent. Anthers 3; 2.4–3.6 mm long; orange. Styles connate below.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Pacific: north-central. North America: Mexico. South America: Mesoamericana.

NOTES Paniceae. Fl Costa Rica 1993.

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