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.

Tripogon africanus

HABIT Perennial; caespitose. Culms erect; 4–20 cm long. Ligule a ciliolate membrane; 0.5 mm long. Leaf-blades filiform; conduplicate, or convolute; 5–10 cm long; 0.5–1 mm wide.

INFLORESCENCE Inflorescence composed of racemes; exserted, or embraced at base by subtending leaf.

Racemes 1; single; flexuous; unilateral; 2–12 cm long. Rhachis subcylindrical and excavated. Spikelet packing broadside to rhachis; regular; 2 -rowed.

Spikelets sunken; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 3–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus bearded. Floret callus hairs 0.33 length of lemma.

GLUMES Glumes persistent; dissimilar; shorter than spikelet; firmer than fertile lemma; recurved at apex (upper glume). Lower glume lanceolate; 1 mm long; 0.25–0.33 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 2.8–4 mm long; 1.1–1.2 length of adjacent fertile lemma; coriaceous; with membranous margins; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 2.3–3.5 mm long; membranous; keeled; 3 -veined. Lemma surface asperulous. Lemma apex dentate; 2 -fid; obtuse; mucronate. Palea 1 length of lemma; 2 -veined. Palea keels wingless.

FLOWER Anthers 3; 1.2 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; isodiametric; 1.5 mm long.

DISTRIBUTION Africa: north and northeast tropical. Asia-temperate: Arabia.

NOTES Eragrostideae. Fl Afr N.

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