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.

Tetrapogon bidentatus

HABIT Perennial; caespitose. Rhizomes short. Basal innovations flabellate (loosely). Culms erect, or geniculately ascending; 25–85 cm long; 3–5 -noded. Culm-nodes pallid; glabrous. Ligule a ciliolate membrane. Leaf-blades 5–15 cm long; 2–3 mm wide. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; ascending; unilateral; 4–10 cm long. Rhachis angular. Spikelet packing broadside to rhachis; regular; 2 -rowed.

Spikelets ascending; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 4–6 mm long; breaking up at maturity; disarticulating above glumes but not between florets. Floret callus pilose.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; gaping. Lower glume lanceolate; 2–3.5 mm long; 0.7 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 3–5 mm long; 1.2–2 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma cuneate; 2.5–3 mm long; coriaceous; much thinner on margins; keeled; winged on margins; 3 -veined. Lemma midvein ciliate. Lemma margins ciliate. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn subapical; 5–9 mm long overall. Palea 2 -veined. Palea keels ciliolate. Apical sterile florets 2–3 in number; barren; in a clump; cuneate; 2–3 mm long. Apical sterile lemmas awned; 1 -awned. Apical sterile lemma awns 2–4 mm long; 2–3 per spikelet in number.

FRUIT Caryopsis with free soft pericarp; oblong; dorsally compressed; biconvex; 1.5 mm long.

DISTRIBUTION Africa: east tropical.

NOTES Cynodonteae. FW 1995.

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