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.

Cymbopogon nervatus

HABIT Annual; culms solitary, or caespitose. Culms erect, or geniculately ascending; 50–180 cm long; 1.5–5 mm diam.; without nodal roots, or with prop roots. Ligule an eciliate membrane; 3 mm long. Leaf-blade base broadly rounded. Leaf-blades 15–30 cm long; 6–10 mm wide; flaccid; glaucous; aromatic.

INFLORESCENCE Synflorescence compound; linear; 10–15 cm long; dense. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole lanceolate; 1.2–1.6 cm long. Peduncle 0.4–0.8 cm long.

Racemes 2; paired; deflexed; 1.2–1.6 cm long. Rhachis fragile at the nodes; semiterete; glabrous on surface; ciliate on margins. Rhachis internodes linear; 2 mm long. 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; 2 mm long; ciliate; hairy on margins.

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

Companion sterile spikelets well-developed; male; oblong; 4–5 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; winged on keels; distinctly veined; 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 lanceolate; dorsally compressed; 4–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; membranous; with oil streaks; 2-keeled; keeled all along; keeled laterally; winged on keel; winged narrowly. Lower glume intercarinal veins distinct; 2 in number. Lower glume surface with V-shaped depression. Lower glume apex emarginate. Upper glume lanceolate; 1-keeled; winged on keel. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline. Fertile lemma lanceolate; 4 mm long; 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; 2 mm long.

DISTRIBUTION Africa: northeast tropical. Asia-temperate: Arabia. Asia-tropical: Indo-China.

NOTES Andropogoneae. FTA 1993.

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