Pennisetum rigidum

HABIT Perennial. Rhizomes elongated. Culms 100–200 cm long. Culm-internodes with small lumen, or solid. Lateral branches ample. Ligule a fringe of hairs. Leaf-blades 14–27 cm long; 5.6–8.6 mm wide. Leaf-blade surface scabrous; rough adaxially; pubescent; hairy abaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; 5–6 cm long; 0.7–0.8 cm wide. Primary panicle branches accrescent to a central axis; with sessile scars on axis. Panicle axis with rounded ribs; puberulous; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets sessile; 1 in the cluster. Involucre composed of bristles; 6 mm long; base truncate. Involucral bristles deciduous with the fertile spikelets; numerous; 12–20 in principal whorl; with longest bristle scarcely emergent; terete; rigid; retrorsely scaberulous; glabrous.

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

GLUMES Glumes shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.5 length of spikelet; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 0.9 length of spikelet; membranous; without keels; 7 -veined. Upper glume apex acute.

FLORETS Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret oblong; 1 length of spikelet; membranous; 7 -veined; acute. Fertile lemma lanceolate; 5 mm long; chartaceous; without keel; 5 -veined. Lemma margins flat. Lemma apex acute. Palea 1 length of lemma; chartaceous.

FLOWER Lodicules absent. Anthers 3. Styles connate below; 0.66 of their length connate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: southern South America.

NOTES Paniceae. Turpe 1994.

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