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 leiostachya

HABIT Perennial; caespitose. Butt sheaths pubescent; persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 90–110 cm long. Ligule a fringe of hairs. Leaf-blades 25–35 cm long; 4–5 mm wide; coriaceous; stiff.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate, or ovate; 10–30 cm long.

Spikelets in threes. Fertile spikelets pedicelled; 3 in the cluster. Pedicels free; unequal.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; compressed slightly; 35–38 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 4 mm long; bearded; pungent. Floret callus hairs 4 mm long (white).

GLUMES Glumes persistent; dissimilar; exceeding apex of florets. Lower glume lanceolate; 26–32 mm long; 0.75–0.85 length of spikelet; chartaceous; dark brown; without keels; 3 -veined. Lower glume surface glabrous. Lower glume apex acute. Upper glume lanceolate; 1 length of spikelet; chartaceous; without keels; 3 -veined. Upper glume surface glabrous. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea; separately deciduous. Lemma of lower sterile floret similar to upper glume; lanceolate; 1 length of spikelet; chartaceous; 5–7 -veined; acute. Fertile lemma oblong; 16–19 mm long; coriaceous; without keel. Lemma surface pubescent. Lemma margins involute; interlocking with palea keels. Lemma apex lobed; 2 -fid; with lanceolate lobes; with lobes 3 mm long; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; subterete below; 80–120 mm long overall; with twisted column; deciduous; abscissing from top of lemma. Palea 2 -veined. Palea keels approximate; thickened; winged; narrowly winged.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Arundinelleae. WDC 1992.

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