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 pedicellata

HABIT Perennial; caespitose. Rhizomes elongated. Butt sheaths pubescent. Culms erect; 100–160 cm long. Lateral branches lacking. Ligule a fringe of hairs. Leaf-blades 7–15 cm long; 4–6 mm wide; stiff. Leaf-blade surface scabrous; rough adaxially. Leaf-blade margins cartilaginous; scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 15–30 cm long. Primary panicle branches appressed; indistinct the panicle almost racemose.

Spikelets in threes. Fertile spikelets pedicelled; 3 in the cluster. Pedicels free; unequal; 2–4 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; compressed slightly; 20–28 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 3.5–4 mm long; bearded; pungent.

GLUMES Glumes persistent; dissimilar; exceeding apex of florets. Lower glume ovate; 0.25 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 obtuse.

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; 8 mm long; coriaceous; without keel; 9 -veined. Lemma surface pubescent. Lemma margins involute; interlocking with palea keels. Lemma apex lobed; 2 -fid; with lanceolate lobes; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; subterete below; 50–70 mm long overall; with twisted column; deciduous; abscissing from top of lemma. Lateral lemma awns arising on apex of lobes; 4–5 mm long. Palea 2 -veined. Palea keels approximate; thickened; winged; narrowly winged.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Africa: south.

NOTES Arundinelleae. Chippindall 1992.

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