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 refractus

HABIT Perennial; caespitose. Culms erect; 50–100 cm long; 2–3 -noded. Culm-nodes glabrous. Ligule an eciliate membrane; 2 mm long. Leaf-blades flat, or revolute; 10–25 cm long; 1.25–2 mm wide; aromatic. Leaf-blade surface scabrous; rough abaxially. Leaf-blade margins scabrous. Leaf-blade apex attenuate.

INFLORESCENCE Synflorescence compound; linear; lax. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole 2–2.5 cm long. Peduncle 0.5–1 cm long.

Racemes 2; paired; deflexed; 1–2 cm long; bearing 2–6 fertile spikelets on each. Rhachis fragile at the nodes; semiterete; ciliate on margins. Rhachis hairs 1.75 mm long. Rhachis internodes linear; 3 mm long. Rhachis internode tip transverse; cupuliform. Raceme-bases flattened; subequal; 1–5 mm long.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; semiterete; 3 mm long; ciliate; with 1.75 mm long hairs.

STERILE SPIKELETS Basal sterile spikelets represented by a single scale; 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; comprising 2 unequal glumes without lemmas; lanceolate; 5 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet glumes coriaceous; 11 -veined; acuminate; pungent.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; acuminate; 4.5–6 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 lanceolate; 1 length of spikelet; chartaceous; 2-keeled; keeled laterally; wingless. Lower glume intercarinal veins distinct; 4–5 in number. Lower glume surface flat. Upper glume lanceolate; chartaceous; 1-keeled; 7 -veined. Upper glume margins ciliolate. Upper glume apex acute, or acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 4.5 mm long; hyaline; 1 -veined; without lateral veins; ciliolate on margins. Fertile lemma lanceolate; 3.5 mm long; hyaline; without keel. Lemma margins ciliolate. Lemma apex entire, or dentate; 2 -fid; mucronate, or awned; 1 -awned. Principal lemma awn from a sinus; straight; 1–12 mm long overall; without a column. Palea absent or minute.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 2.5 mm long.

DISTRIBUTION Australasia: Australia. Pacific: southwestern, south-central, northwestern, and north-central.

NOTES Andropogoneae. Vickery.

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