4. Cymbopogon martini (Roxburgh) Will. Watson in E. T. Atkinson, Himalayan Districts N.W. Prov. India. 392. 1882.
鲁沙香茅 lu sha xiang mao
Andropogon martini Roxburgh, Fl. Ind. 1: 280. 1820; A. schoenanthus Linnaeus var. martini (Roxburgh) J. D. Hooker.
Perennial from a short woody rootstock. Culms tufted, up to 3 m tall, lower nodes often swollen, mealy. Leaf sheaths glabrous; leaf blades lanceolate, usually glaucous below, dark green above, up to 50 × 2–3 cm, glabrous, base cordate, often amplexicaul, apex filiform; ligule 2–4 mm. Spathate panicle narrow, dense, erect, 20–30 cm; spatheoles green becoming reddish, 2–4 cm; racemes 1.5–2 cm; rachis internodes and pedicels ciliate on margins, back sometimes pubescent; pedicel of homogamous pair swollen, barrel-shaped, shiny, fused to internode at base. Sessile spikelet oblong, 3.5–4.5 mm; lower glume flat, deeply grooved below middle (appearing as a line or keel on inside), keels winged above middle, veinless or 2-veined between keels; upper lemma 2-lobed; awn 1.4–1.8 cm. Pedicelled spikelet 3.5–4 mm. Fl. and fr. Jul–Oct. 2n = 20, 40.
Grassy slopes; ca. 1000 m. Sichuan, Yunnan [native to India].
This grass is native to India, but is cultivated elsewhere in the tropics for its oils. Two forms can be distinguished in the field, each with a different oil content, but the habit differences are not evident in herbarium material. The cultivar 'Motia' yields palmerosa oil and 'Sofia' yields ginger-grass oil.
The name "Cymbopogon lanceifolium L. Liu" (Fl. Reipubl. Popularis Sin. 10(2): 194. 1997) was not validly published because no Latin description was provided. It appears to be based on a specimen of C. martini with a rather lax panicle.