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Descriptions

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

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

Cymbopogon polyneuros

HABIT Perennial; caespitose. Rootstock evident. Culms 45–120 cm long. Ligule an eciliate membrane. Leaf-blade base cordate. Leaf-blades 8–20 cm long; 4–10 mm wide; glaucous; aromatic. Leaf-blade apex attenuate; filiform.

INFLORESCENCE Synflorescence compound; paniculate; 4–16 cm long; dense. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed.

Racemes 2; paired; deflexed; 1–2 cm long. Rhachis fragile at the nodes; semiterete; ciliate on margins. Rhachis hairs 2 mm long. Rhachis internodes linear. Rhachis internode tip transverse; cupuliform. Raceme-bases flattened; subequal.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; semiterete; ciliate; with 2 mm long hairs.

STERILE SPIKELETS Basal sterile spikelets well-developed; 2 in number (lower raceme); 0 in upper raceme; sessile and pedicelled. Basal sterile spikelet pedicels free; linear. Basal sterile spikelets equalling fertile.

Companion sterile spikelets well-developed; male; lanceolate; 4.5–5 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; 7 -veined; acute; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 3.5–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; 2-keeled; keeled laterally; winged on keel; winged above. Lower glume surface with V-shaped depression. Upper glume lanceolate; 1-keeled. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline. Fertile lemma lanceolate; hyaline; without keel. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 8–16 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

DISTRIBUTION Asia-tropical: India and Indo-China.

NOTES Andropogoneae. FTEA.

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