Cenchrus ciliaris

HABIT Perennial; caespitose. Rhizomes short. Butt sheaths distinctly ribbed; sparsely hairy, or pubescent, or pilose. Basal innovations extravaginal. Culms geniculately ascending; 10–50 cm long; 1–4 mm diam.; wiry. Lateral branches sparse. Leaves basal and cauline. Leaf-sheaths loose; open for most of their length; with flat margins; 5–8.5 cm long; mostly shorter than adjacent culm internode; keeled; striately veined; scaberulous; glabrous on surface, or pilose; outer margin glabrous, or hairy. Leaf-sheath oral hairs scanty, or ciliate. Ligule a fringe of hairs; 0.2–2 mm long. Collar glabrous. Leaf-blades 3–25 cm long; 4–10 mm wide. Leaf-blade midrib conspicuous; prominent beneath. Leaf-blade venation distinct. Leaf-blade surface ribbed; scaberulous; glabrous, or pilose; sparsely hairy; hairy on both sides (or glabrous); with tubercle-based hairs (at times). Leaf-blade margins unthickened; eglandular; glabrous, or ciliate. Leaf-blade apex acuminate; hardened.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear to oblong; 2–14 cm long; 1–2.6 cm wide. Primary panicle branches accrescent to a central axis; with sessile scars on axis. Panicle axis angular; puberulous; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets sessile; 1–4 in the cluster. Involucre composed of bristles; connate into a disc below (0.5–1mm diam); with 0.2–0.3(–0.5) mm connate; 6–12 mm long; base obconical. 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; 8–16 mm long; flattened (at least base of longest bristle); without grooves, or grooved on the face; flexible (often wavy); antrorsely scaberulous; ciliate.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; acute; 2–5.5 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; subequal in width; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.2–0.5 length of spikelet; hyaline; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 0.4–1 length of spikelet; hyaline; without keels; 1–3 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret ovate; 1 length of fertile lemma; membranous; 5 -veined; acute; mucronate. Fertile lemma ovate; dorsally compressed; lanceolate in profile; 2–5.5 mm long; chartaceous; pallid; without keel; 5 -veined. Lemma margins covering most of palea. Lemma apex acute; mucronate. Palea ovate; 1 length of lemma; chartaceous; 2 -veined. Palea apex acute.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 1.5 mm long. Stigmas 2; protogynous; terminally exserted.

FRUIT Caryopsis obovoid; dorsally compressed; 1–1.3 mm long; dark brown; glabrous; truncate, or obtuse; apex unappendaged.

DISTRIBUTION Europe: southeastern. Africa: north, Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. Asia-temperate: western Asia, Arabia, and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern, south-central, northwestern, and north-central. North America: Mexico. South America: Mesoamericana, Caribbean, western South America, Brazil, and southern South America.

NOTES Paniceae. VJN 1993.

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