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.

Oplismenus thwaitesii

HABIT Annual. Culms prostrate; 10–25 cm long. Ligule a ciliate membrane. Leaf-blades lanceolate, or ovate; 1–3 cm long; 2.5–5 mm wide. Leaf-blade venation with obscure cross veins.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 3–4; borne along a central axis; unilateral; 1–2 cm long. Central inflorescence axis 3–6 cm long. Rhachis angular; glabrous on surface. Spikelet packing lax.

Spikelets in pairs. Fertile spikelets sessile and pedicelled; 2 in the cluster; subequal, or the lower smaller. Pedicels oblong.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2.5–3.5 mm long; falling entire.

GLUMES Glumes similar, or dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 1 length of upper glume; 0.5–0.75 length of spikelet; herbaceous; 1-keeled; 5 -veined. Lower glume surface pubescent. Lower glume apex acute; awned; 1 -awned. Lower glume awn 0.5–1.5 mm long; without vesture (but scaberulous). Upper glume ovate; herbaceous; 1-keeled; 5–7 -veined. Upper glume surface pubescent. Upper glume apex obtuse; muticous, or mucronate.

FLORETS Basal sterile florets barren; with palea, or without significant palea. Lemma of lower sterile floret ovate; 1 length of spikelet; membranous; 1-keeled; 7–11 -veined; pubescent; emarginate; mucronate. Fertile lemma oblong; dorsally compressed; 2–2.5 mm long; coriaceous; shiny; without keel; 7 -veined. Lemma margins involute. Lemma apex acute; laterally pinched. Palea involute; coriaceous; without keels.

DISTRIBUTION Asia-tropical: India.

NOTES Paniceae. FTEA.

ADDITIONAL CHARACTERS Spikelet pairs 2–5mm apart.

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