23. Cymbopogon khasianus (Munro ex Hackel) Stapf ex Bor, Indian Forest Rec., Bot. 1: 92. 1938.
卡西香茅 ka xi xiang mao
Andropogon nardus Linnaeus var. khasianus Munro ex Hackel in A. Candolle & C. Candolle, Monogr. Phan. 6: 603. 1889.
Perennial from a stout rootstock. Culms fairly slender to robust, up to 2 m tall, 3–6 mm in diam., nodes purple, glabrous, or puberulous to tomentose with creamy hairs. Leaf sheaths glabrous or basal part above node pubescent, auricles to 6 mm at mouth; leaf blades linear, slightly glaucous or sometimes purplish, 40–60 × 0.7–1 cm, abaxial surface usually tomentose at sheath junction, otherwise glabrous, base gradually narrowed, apex filiform; ligule 1.5–4 mm. Spathate compound panicle narrow, erect, decompound, often purplish, ca. 50 cm or more, much branched, spathate compound clusters dense; spatheoles 1.2–2 cm; racemes 1.2–1.5(–2) cm; rachis internodes and pedicels ciliate on margins, hairs ca. 1.5 mm; pedicel of homogamous pair not swollen. Sessile spikelet elliptic-oblong, 4–5 × 0.9–1.2 mm; lower glume flat or shallowly concave below middle, occasionally puberulous in depression, often transversely wrinkled, sharply 2-keeled throughout, keels winged above middle, wings 0.1–0.3 mm wide, (2–)5(–7)-veined between keels; upper lemma awned; awn 0.8–1.1 cm. Pedicelled spikelet 3–5 mm. Fl. and fr. Sep–Nov. 2n = 60.
Hill slopes, forest margins; 800–2000 m. Guangxi, Yunnan [Bhutan, India, Myanmar, N Thailand].
This is a variable species intergrading with several related species, including Cymbopogon flexuosus, C. microstachys, and C. pendulus. Cymbopogon khasianus can be recognized by its erect, often purplish compound panicle and sessile spikelets with a wrinkled, winged, several-veined lower glume. The wing width and number of veins can vary even within the same panicle.