Cymbopogon commutatus

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm. Culms 15–150 cm long. Ligule an eciliate membrane. Leaf-blades filiform, or linear; flat, or involute; 10–50 cm long; 1–4 mm wide; aromatic. Leaf-blade surface smooth, or scaberulous.

INFLORESCENCE Synflorescence compound; linear, or paniculate; 5–35 cm long; dense. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed.

Racemes 2; paired; deflexed; 1.5–3 cm long; bearing 5–8 fertile spikelets on each. 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; with normal internodes, or with swollen internode in lower raceme; sessile and pedicelled. Basal sterile spikelet pedicels swollen in lower raceme. Basal sterile spikelets equalling fertile.

Companion sterile spikelets well-developed; male; lanceolate; 4.5–7 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; 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; 4–7 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 linear; 1 length of spikelet; chartaceous; 2-keeled; keeled above; keeled laterally; wingless. Lower glume intercarinal veins absent, or obscure; 0(–3) in number. Lower glume surface concave; impressed with a boss blocking lower end; glabrous, or pubescent. Lower glume apex emarginate. 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; 10–20 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

DISTRIBUTION Africa: west tropical, northeast tropical, and east tropical. Asia-temperate: western Asia and Arabia. Asia-tropical: India.

NOTES Andropogoneae. FTEA.

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