20. Cymbopogon traninhensis (A. Camus) Soenarko, Reinwardtia. 9: 347. 1977.
横香茅 heng xiang mao
Cymbopogon confertiflorus (Steudel) Stapf var. traninhensis A. Camus, Bull. Mus. Natl. Hist. Nat. 26: 565. 1920; C. khasianus (Munro ex Hackel) Stapf ex Bor var. nagensis Bor.
Perennial. Culms tufted, 1.5–2 cm tall, ca. 5 mm in diam., nodes glabrous or pubescent. Leaf sheaths glabrous or pubescent at base above node; leaf blades linear, up to 75 × 1–1.3 cm, abaxial surface bearded at sheath junction, otherwise glabrous, margins scabrid, base gradually narrowed, apex finely acuminate; ligule 3–6 mm. Spathate compound panicle narrow, erect or slightly spreading, usually purplish, ca. 50 cm or more, branched several times, spathes in lax clusters; spatheoles 1–2 cm; racemes 2–2.5 cm; rachis internodes and pedicels ciliate on margins;pedicel of homogamous pair not swollen. Sessile spikelet narrowly obovate, 5.5–7 × 1–1.5 mm; lower glume flat or shallowly concave below middle, frequently pubescent in depression, often transversely wrinkled, sharply 2-keeled throughout, keels winged above middle, wings 0.3–0.5 mm wide, 2–5-veined between keels; upper lemma awned; awn 1–2 cm. Pedicelled spikelet 5–5.5 mm.
Dry rocky or grassy hill slopes. Yunnan [NE India, Laos, Myanmar, N Thailand].
This species is very close to Cymbopogon khasianus, with the erect, purplish compound panicle typical of that species, but has slightly longer, more broadly winged spikelets.