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.

Rhytachne triaristata

HABIT Annual; caespitose. Culms slender; 40–60 cm long; 3–4 -noded. Ligule a ciliolate membrane. Leaf-blades filiform; convolute; 10–20 cm long; 1.5–2 mm wide. Leaf-blade surface puberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; smoothly terete; 5–12 cm long. Rhachis fragile at the nodes; semiterete; glabrous on surface; glabrous on margins. Rhachis internodes cuneate; 4–6 mm long. Rhachis internode tip transverse; crateriform; with simple rim.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; foliaceous; curved; 5–8 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets represented by awns; comprising 2 awns; 5–7 mm long; deciduous with the fertile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent; base truncate; with central peg; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; without keels; winged on margins; winged narrowly; 6–7 -veined. Lower glume surface rugose (strongly). Lower glume margins ciliolate. Lower glume apex acuminate; awned; 2 -awned. Lower glume awn 5–7 mm long. Upper glume lanceolate; membranous; 3 -veined. Upper glume awned; 1 -awned. Upper glume awn 5–7 mm long.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret lanceolate; 2 mm long; hyaline; 1 -veined; without lateral veins; acute. Fertile lemma lanceolate; 2 mm long; hyaline; without keel; 1 -veined. Lemma apex acute. Palea 0.5 length of lemma.

FLOWER Anthers 3; 0.5–0.7 mm long.

DISTRIBUTION Africa: west tropical, west-central tropical, northeast tropical, and southern tropical.

NOTES Andropogoneae. FTA.

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