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 undulatifolius

HABIT Perennial. Culms prostrate; 15–50 cm long; rooting from lower nodes. Culm-internodes distally pilose. Leaf-sheaths pilose. Ligule a ciliate membrane. Leaf-blade base asymmetrical. Leaf-blades lanceolate, or ovate; 1–7 cm long; 4–15 mm wide. Leaf-blade venation with obscure cross veins. Leaf-blade surface hispid; sparsely hairy; hairy on both sides. Leaf-blade apex acuminate, or acute (bluntly).

INFLORESCENCE Inflorescence composed of racemes.

Racemes 5–11; borne along a central axis; cuneate; unilateral; 0.5–1.5 cm long; bearing few fertile spikelets; bearing 2–6 fertile spikelets on each (in a fascicle). Central inflorescence axis 2–14 cm long; pilose. Rhachis angular; glabrous on surface, or pilose on surface. Spikelet packing crowded.

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; 2.5–4 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 glabrous, or pubescent. Lower glume apex acute; awned; 1 -awned. Lower glume awn 7–14 mm long; viscid. Upper glume ovate; herbaceous; 1-keeled; 5–7 -veined. Upper glume surface glabrous, or pubescent. Upper glume apex obtuse; muticous, or awned. Upper glume awn 0–4 mm long.

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; glabrous, or 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 Europe: central, southwestern, and southeastern. Africa: west-central tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. Asia-temperate: Caucasus, western Asia, China, and eastern Asia. Asia-tropical: India and Malesia. Australasia: Australia. North America: south-central USA and southeast USA. South America: Caribbean.

NOTES Paniceae. SAR 2002.

ADDITIONAL CHARACTERS Spikelet pairs 0.5–2mm apart.

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