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.

Tristachya auronitens

HABIT Perennial; caespitose; clumped densely. Butt sheaths pubescent; persistent and investing base of culm; with compacted dead sheaths. Culms erect; 45 cm long; 2 -noded. Culm-nodes pubescent. Ligule a fringe of hairs. Leaf-blade apex hardened.

INFLORESCENCE Inflorescence a panicle; comprising 3 fertile spikelets, or 6 fertile spikelets (1–2 triads).

Spikelets in threes. Fertile spikelets pedicelled; 3 in the cluster. Pedicels fused to each other; united wholly.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; compressed slightly; 33 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; pungent.

GLUMES Glumes persistent; dissimilar; reaching apex of florets. Lower glume lanceolate; 0.66 length of spikelet; chartaceous; light brown, or dark brown; without keels; 3 -veined. Lower glume surface glabrous. Lower glume apex acute. Upper glume lanceolate; 1 length of spikelet; chartaceous; light brown, or dark brown; without keels; 3 -veined. Upper glume surface glabrous.

FLORETS Basal sterile florets male; with palea; separately deciduous. Lemma of lower sterile floret similar to upper glume; lanceolate; 0.8 length of spikelet; chartaceous; 3 -veined; acute. Fertile lemma oblong; 11 mm long; coriaceous; without keel; 9 -veined. Lemma surface glabrous. Lemma margins involute; interlocking with palea keels. Lemma apex lobed; 2 -fid; with lobes 3–5 mm long; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 70 mm long overall; with twisted column; deciduous; abscissing from top of lemma. Column of lemma awn 35 mm long. Palea 2 -veined. Palea keels approximate.

FLOWER Ovary pubescent on apex.

DISTRIBUTION Africa: west-central tropical.

NOTES Arundinelleae. Phipps 2005.

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