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.

Ctenium elegans

HABIT Annual; caespitose. Glands wart-like. Culms geniculately ascending; 90–120 cm long. Ligule an eciliate membrane; erose. Leaf-blades flat; 20–30 cm long; 1–3 mm wide; aromatic. Leaf-blade apex filiform.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; straight, or arcuate; unilateral; 20–30 cm long. Rhachis semiterete; glabrous on surface; pubescent on margins; terminating in a barren extension; extension subulate. Spikelet packing broadside to rhachis; crowded; regular; 2 -rowed.

Spikelets pectinate; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets cuneate; laterally compressed; 4–6 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; dissimilar; exceeding apex of florets; gaping. Lower glume lanceolate; 0.25 length of upper glume; hyaline; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex setaceously attenuate. Upper glume lanceolate; 4–6 mm long; 2 length of adjacent fertile lemma; membranous; glandular (on keel); 1-keeled; 2 -veined. Upper glume primary vein tuberculate. Upper glume surface asperulous. Upper glume apex setaceously attenuate; awned; 1 -awned. Upper glume awn dorsal and oblique; 0.1–2 mm long.

FLORETS Basal sterile florets dissimilar; barren; without significant palea; attached to and deciduous with the fertile. Lemma of lower sterile floret oblong; 0.75 length of fertile lemma; hyaline; glandular (yellow, on margins); 1-keeled; 3 -veined; pilose; obtuse; awned. Awn of lower sterile floret dorsal; 6–10 mm long. Lemma of upper sterile floret oblong; 1.1 length of lower sterile floret; hyaline; tuberculate (yellow glands on margins); ciliate on margins (and with long apical bristles); obtuse; awned. Awn of upper sterile floret subapical; 6–10 mm long. Fertile lemma ovate; 2–3 mm long; membranous; keeled; 3 -veined. Lemma surface with conspicuous apical hairs (2–8 in number). Lemma hairs 2 mm long. Lemma apex acute; awned; 1 -awned. Principal lemma awn subapical; 6–10 mm long overall. Palea 2 -veined. Palea keels tuberculate (yellow glands).

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Africa: west tropical, west-central tropical, and northeast tropical. Asia-temperate: Arabia.

NOTES Cynodonteae. FWTA.

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