GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Cenchrus gracillimus

HABIT Annual; caespitose. Culms 15–60 cm long. Leaf-sheaths keeled; glabrous on surface, or pilose. Ligule a fringe of hairs; 0.2–0.6 mm long. Leaf-blades 4.5–17 cm long; 1.1–3.3 mm wide. Leaf-blade surface smooth, or scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; loose (internodes 4–10mm); 2–6.8 cm long; 0.8–1.9 cm wide. Primary panicle branches accrescent to a central axis; with sessile scars on axis. Panicle axis angular; scabrous; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets sessile; 1–3 in the cluster. Involucre composed of bristles; connate into a cup below; ovate; 5.2–12.9 mm long; base obconical; base glabrous. Involucral bristles deciduous with the fertile spikelets; emerging irregularly from body of a burr; 3.2–6 mm long; flattened; rigid; retrorsely scaberulous; glabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; acuminate; 4–6.5 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 1.4–3.1 mm long; 0.3–0.5 length of spikelet; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 3.2–5.4 mm long; 0.75 length of spikelet; membranous; without keels; 3–5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret ovate; 4.1–6 mm long; 1 length of spikelet; membranous; 3–5 -veined; acute. Fertile lemma ovate; 3.9–6.5 mm long; coriaceous; much thinner on margins; without keel; 3 -veined. Lemma margins flat. Lemma apex obtuse. Palea coriaceous.

FLOWER Anthers 0.9–1.9 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: southeast USA. South America: Caribbean.

NOTES Paniceae. De Lisle.

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