Cymbopogon bombycinus

HABIT Perennial; caespitose. Butt sheaths pubescent; persistent and investing base of culm; with compacted dead sheaths, or curly dead sheaths. Basal innovations extravaginal. Culms erect; 30–100 cm long. Culm-internodes distally glabrous. Culm-nodes bearded. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 3–5.5 mm long; membranous. Leaf-blades 15–25 cm long; 2–4.5 mm wide; aromatic. Leaf-blade surface scaberulous; rough abaxially; glabrous.

INFLORESCENCE Synflorescence compound; linear; 25 cm long; dense. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole elliptic; 2–3.4 cm long; herbaceous; pubescent (on margins). Peduncle 0.6 cm long; pubescent above.

Racemes 2; paired; erect; 1.7–2.2 cm long. Rhachis fragile at the nodes; semiterete; villous on surface. Rhachis internodes linear. Rhachis internode tip transverse; cupuliform. Raceme-bases flattened; subequal; pilose.

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

STERILE SPIKELETS Basal sterile spikelets rudimentary; 2 in number (lower raceme); 0 in upper raceme; with normal internodes; sessile and pedicelled. Basal sterile spikelet pedicels free; linear. Basal sterile spikelets smaller than fertile.

Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas; lanceolate; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; 7 -veined; glabrous; acute; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 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. Lower glume intercarinal veins absent. Lower glume surface concave. Lower glume apex acuminate. 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; 9–18 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; orbicular, or obovoid; 2–5 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Soenarko 1993.

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