Cymbopogon annamensis

HABIT Perennial; caespitose. Basal innovations extravaginal. Culms geniculately ascending; 65–100 cm long; wiry. Culm-internodes distally glabrous. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 0.5–1.5 mm long. Leaf-blade base broadly rounded. Leaf-blades 20–40 cm long; 3–4 mm wide; aromatic. Leaf-blade surface glabrous.

INFLORESCENCE Synflorescence compound; linear; 20 cm long; lax. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole elliptic; 2.5 cm long.

Racemes 2; paired; deflexed; 1.8–2 cm long. Rhachis fragile at the nodes; semiterete; glabrous on surface; ciliate on margins. Rhachis internodes linear. Rhachis internode tip transverse; cupuliform. Raceme-bases flattened; unequal (the longer measured).

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; semiterete; ciliate.

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 fused to internode in lower raceme; swollen in lower raceme. Basal sterile spikelets equalling fertile.

Companion sterile spikelets well-developed; male; lanceolate; 3.8 mm long; shorter than 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 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; chartaceous; 2-keeled; keeled all along; keeled laterally; winged on keel; winged broadly. Lower glume intercarinal veins absent, or obscure; 0–2 in number. 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; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 15 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Asia-temperate: China. Asia-tropical: Indo-China.

NOTES Andropogoneae. Soenarko 1993.

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