Cymbopogon giganteus

HABIT Perennial; caespitose; clumped loosely. Butt sheaths withering. Basal innovations extravaginal. Culms erect; 100–300 cm long; without nodal roots, or with prop roots. Ligule an eciliate membrane; 0.3–2 mm long; scarious. Leaf-blade base broadly rounded, or cordate. Leaf-blades linear, or lanceolate; 15–60 cm long; 8–30 mm wide; herbaceous; dark green; aromatic. Leaf-blade surface smooth. Leaf-blade apex attenuate.

INFLORESCENCE Synflorescence compound; linear; 20–70 cm long; dense, or lax. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole lanceolate; 1–2 cm long; herbaceous.

Racemes 2; paired; deflexed; 1–1.5 cm long. Rhachis fragile at the nodes; semiterete; ciliate on margins. Rhachis hairs 0.5–1 mm long. Rhachis internodes linear; 2.5–3 mm long. Rhachis internode tip transverse; cupuliform. Raceme-bases flattened; subequal; 0.5–1.5 mm long; pubescent, or pilose.

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; 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; 3.5–5 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; 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 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 oblong; 1 length of spikelet; membranous; without oil streaks (or obscure); 2-keeled; keeled laterally; winged on keel; winged narrowly. Lower glume intercarinal veins absent, or obscure. Lower glume surface with V-shaped depression. Lower glume apex emarginate. Upper glume lanceolate; 1-keeled; 1–3 -veined. Upper glume primary vein ciliate. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret linear; 2–4 mm long; hyaline. Fertile lemma linear, or lanceolate; 3 mm long; hyaline; without keel; 1 -veined. Lemma margins ciliate. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; muticous (rarely), or awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–17 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3; 1.5 mm long.

DISTRIBUTION Africa: west tropical, west-central tropical, northeast tropical, east tropical, and southern tropical.

NOTES Andropogoneae. FTEA 1997.

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