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.

Ischaemum copeanum

HABIT Annual; mat forming. Culms prostrate; 20–40 cm long; rooting from lower nodes. Culm-nodes glabrous, or pubescent. Leaf-sheaths 1.5 cm long; mostly shorter than adjacent culm internode; glabrous on surface. Ligule an eciliate membrane; 1–2 mm long; acute. Leaf-blade base broadly rounded, or cordate. Leaf-blades lanceolate, or oblong; 2–5 cm long; 4–10 mm wide. Leaf-blade surface hirsute; sparsely hairy; with tubercle-based hairs. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; subtended by an inflated leaf-sheath; with 1–2 peduncles per sheath.

Racemes 2; paired; 2–3 cm long. Rhachis fragile at the nodes; angular; pilose on surface; villous on margins. Rhachis internodes oblong; 3–3.5 mm long; flat and forming a U or V shape with the pedicel in rear view and with the lower often bearing triads. Rhachis internode tip transverse; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels clavate; 0.5–1 mm long; 0.33 length of internode; villous.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; linear, or oblong; laterally compressed; 4–4.5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet callus oblong. Companion sterile spikelet glumes chartaceous; keeled; scaberulous; hirsute. Companion sterile spikelet lemmas 2; enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 4–4.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; chartaceous; 2-keeled; keeled all along; keeled laterally; keeled obtusely; winged on keel; winged narrowly; 11–13 -veined. Lower glume lateral veins obscure. Lower glume surface convex; scabrous; rough above; villous; hairy below. Upper glume lanceolate; chartaceous; with membranous margins; 1-keeled; 3 -veined. Upper glume primary vein obscure, or distinct. Upper glume margins ciliolate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate, or elliptic; 3.5–4 mm long; hyaline; 3–5 -veined; obscurely veined; ciliolate on margins; fringed above. Palea of lower sterile floret 3–3.5 mm long. Fertile lemma oblong; 3–3.5 mm long; hyaline; without keel; 3 -veined. Lemma lateral veins obscure. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–15 mm long overall; with twisted column. Column of lemma awn 4–6 mm long; glabrous. Palea 2.5–3 mm long; hyaline; 2 -veined. Palea surface papillose (above).

FLOWER Anthers 3; 1.5–3 mm long.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Gr Kerala 1997.

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