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.

Ischaemum malabaricum

HABIT Annual. Culms decumbent, or rambling; weak; 30–50 cm long. Culm-nodes bearded. Leaf-sheaths 1–6 cm long; mostly shorter than adjacent culm internode; striately veined; glabrous on surface. Ligule an eciliate membrane; 2–3 mm long. Leaf-blade base cordate, or sagittate. Leaf-blades lanceolate; 1–10 cm long; 5–15 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy. Leaf-blade apex acute, or acuminate.

INFLORESCENCE Inflorescence composed of racemes; subtended by a spatheole. Spatheole 2–8 cm long; pilose.

Racemes 2; paired; appressed back to back; 2–6 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes oblong; 2–3 mm long. Rhachis internode tip transverse; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels oblong; 2 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; elliptic; laterally compressed; 3.5–4 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; 9–11 -veined; glabrous, or pilose. Companion sterile spikelet lemmas 2; enclosed by glumes; 2.5–3.5 mm long; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 3.5–4.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded; base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic, or oblong; 3–4 mm long; 1 length of spikelet; chartaceous; 2-keeled; keeled all along; keeled laterally; 11–13 -veined. Lower glume surface flat; smooth; villous. Lower glume hairs 1–2 mm long. Lower glume apex acute. Upper glume lanceolate; 3–3.5 mm long; chartaceous; with hyaline margins; 1-keeled; 3–5 -veined. Upper glume surface pubescent. Upper glume margins ciliolate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret elliptic, or oblong; 3.5–4 mm long; hyaline; 2-keeled; 3–5 -veined; ciliolate on margins; acute. Palea of lower sterile floret 3–3.5 mm long. Fertile lemma oblong; 2.5–3 mm long; membranous; without keel; 3 -veined. Lemma lateral veins obscure. Lemma margins ciliolate. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 12–15 mm long overall; with twisted column. Column of lemma awn 5 mm long; glabrous. Palea lanceolate, or oblong; 2–2.5 mm long; hyaline; 2 -veined.

FLOWER Lodicules 2; 0.4 mm long. Anthers 3; 1–2 mm long; yellow.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Sreeekuma 1999.

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