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 vembanadense

HABIT Perennial; caespitose. Culms prostrate; 150–160 cm long. Culm-internodes smooth; distally pruinose. Culm-nodes swollen; glabrous. Lateral branches ample. Leaf-sheaths loose; outer margin hairy. Ligule an eciliate membrane; 5–10 mm long. Leaf-blade base with a false petiole. Leaf-blades lanceolate; 7–15 cm long; 10–15 mm wide. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; appressed back to back; 4–7 cm long. Rhachis fragile at the nodes; angular; smooth on surface. Rhachis internodes oblong; 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 oblong; 2 mm long.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; laterally compressed; 4–7 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; tuberculate on margins. Companion sterile spikelet lemmas 2; enclosed by glumes; 4.5 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 6.5–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; much thinner above; 2-keeled; keeled all along; keeled laterally; wingless. Lower glume surface flat; rugose. Lower glume apex acute. Upper glume ovate; 1 length of spikelet; coriaceous; 1-keeled. Upper glume margins ciliate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; 6 mm long; hyaline; 3 -veined; ciliate on margins. Palea of lower sterile floret 5 mm long. Fertile lemma oblong; 5 mm long; membranous; without keel. Lemma margins ciliate. Lemma apex lobed; 2 -fid; muticous, or awned; 1 -awned. Principal lemma awn from a sinus; curved. Palea 4–5 mm long.

FLOWER Anthers 3; 2 mm long.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Pabil & Cruz 2006.

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