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.

Ctenium somalense

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Glands wart-like. Culms erect; 30–100 cm long; wiry. Ligule an eciliate membrane; erose. Leaf-blades flat, or involute; 10–35 cm long; 1–3 mm wide.

INFLORESCENCE Inflorescence composed of racemes. Peduncle hirsute above (at tip).

Racemes 1; single; arcuate; unilateral; 5–10 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; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 4.5–5.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose.

GLUMES Glumes persistent; dissimilar; exceeding apex of florets; firmer than fertile lemma; gaping. Lower glume lanceolate; 0.3–0.5 length of upper glume; herbaceous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume surface hispidulous. Lower glume apex acuminate; mucronate. Upper glume lanceolate; 4.5–5 mm long; 1.4–1.7 length of adjacent fertile lemma; herbaceous; with hyaline margins; glandular; 1-keeled; 2 -veined. Upper glume primary vein tuberculate. Upper glume surface hispidulous. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn dorsal and oblique; 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 elliptic; 1.7–2.6 mm long; 0.6–0.7 length of fertile lemma; membranous; 1-keeled; glabrous, or puberulous (sparsely); hairy between veins; ciliate on midvein; ciliate on margins; obtuse; awned. Awn of lower sterile floret subapical. Lemma of upper sterile floret lanceolate; 2.5–3 mm long; 0.7–0.9 length of lower sterile floret; membranous; glabrous, or pubescent; ciliate on midvein; ciliate on margins; obtuse; awned. Awn of upper sterile floret dorsal (with an oblong tongue 0.5–1 mm long above insertion). Fertile lemma ovate; 2.7–3.5 mm long; membranous; keeled; 3 -veined. Lemma midvein ciliate. Lemma margins ciliate. Lemma hairs 2 mm long. Lemma apex acute; awned; 1 -awned. Principal lemma awn subapical; 3.5–5 mm long overall. Palea 2 -veined. Palea keels ciliolate. Apical sterile florets 2 in number; separate; linear; 1–2.5 mm long. Apical sterile lemmas awned; 1 -awned. Apical sterile lemma awns 1 per spikelet in number.

FRUIT Caryopsis with adherent pericarp; ellipsoid.

DISTRIBUTION Africa: west-central tropical, northeast tropical, east tropical, southern tropical, and western Indian ocean.

NOTES Cynodonteae. FTEA.

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