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 flumineum

HABIT Perennial; caespitose. Butt sheaths pubescent. Culms geniculately ascending; 25–30 cm long; wiry. Culm-nodes bearded. Ligule an eciliate membrane; 1.5–2 mm long. Leaf-blades elliptic; 5–10 cm long; 3–5 mm wide. Leaf-blade surface smooth, or scaberulous; glabrous, or pilose; sparsely hairy; with tubercle-based hairs. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; appressed back to back; 4–5 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes linear; 3 mm long; flat and forming a U or V shape with the pedicel in rear view. Rhachis internode tip transverse; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; 2.5 mm long; 0.5 length of fertile spikelet; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; pilose; awned; one glume awned; with 2.5 mm long awn. Companion sterile spikelet lemmas 1-awned; with 10 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or elliptic; dorsally compressed; 5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 1 mm long; pilose; base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 1 length of spikelet; coriaceous; much thinner above; 2-keeled; keeled above; keeled laterally. Lower glume surface convex. Lower glume margins ciliate. Lower glume apex dentate; 2 -fid; mucronate; 2 -awned (mucronate). Upper glume lanceolate; coriaceous; 1-keeled; 3 -veined. Upper glume primary vein ciliate. Upper glume awned; 1 -awned. Upper glume awn 2–3 mm long.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; 4 mm long; membranous; 5 -veined. Fertile lemma oblong; 2–2.5 mm long; membranous; without keel; 3 -veined. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 13 mm long overall; with twisted column. Column of lemma awn glabrous.

FLOWER Anthers 3; 1–1.25 mm long.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Bor 1994.

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