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Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Ischaemum burmanicum

HABIT Annual. Culms 40 cm long. Ligule an eciliate membrane; 1–1.5 mm long. Leaf-blade base sagittate; without a false petiole, or with a brief petiole-like connection to sheath. Leaf-blades 10 cm long; 15 mm wide; flaccid. Leaf-blade surface pilose; sparsely hairy; hairy on both sides; with tubercle-based hairs. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; 4 cm long. Rhachis fragile at the nodes; semiterete. Rhachis internodes inflated; 5 mm long; with the lower often bearing triads (1 sessile, 2 pedicelled). Rhachis internode tip transverse; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster; heteromorphic (lowest awnless). Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels oblong; 0.5 mm long; 0.05 length of fertile spikelet; bearing a few hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; laterally compressed; 6.5 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; muricate; pilose. Companion sterile spikelet lemmas 2; enclosed by glumes; entire; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or oblong; dorsally compressed; 8.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 2 mm long; bearded; base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 6.5 mm long; 1 length of spikelet; coriaceous; 2-keeled; keeled all along; keeled laterally. Lower glume surface rugose; pilose. Lower glume hairs white; 3 mm long. Lower glume apex acute. Upper glume lanceolate; coriaceous; much thinner above; 1-keeled; winged on keel (narrowly); 3 -veined.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate, or elliptic; 5.5 mm long; hyaline; 1 -veined; without lateral veins; truncate. Fertile lemma oblong; 4.5 mm long; hyaline; without keel; 1 -veined. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 15 mm long overall; with twisted column. Column of lemma awn 7 mm long; glabrous. Palea 1 length of lemma.

FLOWER Anthers 3; 3.5 mm long.

DISTRIBUTION Asia-tropical: Indo-China.

NOTES Andropogoneae. Bor 1993.

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