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.

Rhytachne robusta

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Culms 60–120 cm long; 2–3 -noded. Leaf-sheaths glabrous on surface, or pilose. Ligule a ciliolate membrane; 3 mm long. Leaf-blades 15–30 cm long; 2–4 mm wide. Leaf-blade surface glabrous, or pilose. Leaf-blade margins scabrous. Leaf-blade apex filiform.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; smoothly terete; 10–17 cm long. Rhachis fragile at the nodes; semiterete; 2 mm wide; glabrous on surface; ciliate on margins. Rhachis internodes cuneate; 9–10 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; 7–8 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets represented by barren pedicels, or rudimentary; comprising 2 subequal glumes without lemmas; 0–2 mm long; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 7–9 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; 4–5 -veined. Lower glume surface asperulous. Lower glume apex acute; muticous. Upper glume lanceolate; membranous; 5 -veined. Upper glume margins ciliolate. Upper glume apex acute; muticous.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; hyaline; 2 -veined; ciliolate on margins; acute. Fertile lemma lanceolate; hyaline; without keel; 3 -veined. Lemma margins ciliolate. Lemma apex acute.

FLOWER Anthers 3; 4 mm long.

DISTRIBUTION Africa: southern tropical and south.

NOTES Andropogoneae. FTA.

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