沙生蔗茅 sha sheng zhe mao

Andropogon ravennae Linnaeus, Sp. Pl., ed. 2, 2: 1481. 1763; Erianthus ravennae (Linnaeus) P. Beauvois.

Perennial, forming large clumps. Culms (1.5–)2–3(–4) m tall, ca. 1 cm in diam., lower nodes yellowish villous, glabrous below panicle. Lower leaf sheaths hirsute with tubercle-based hairs, upper sheaths smooth; leaf blades 50–120 × 0.5–1.8 cm, woolly above ligule with long yellowish hairs, otherwise glabrous, margins scabrid, tapering to midrib at base, apex filiform; ligule a narrow rim, back villous with ca. 2 mm hairs. Panicle dense, lobed, 30–50 × 10–15 cm, grayish sometimes tinged pink, axis glabrous, branches much branched; racemes short, crowded, with 3–4 joints; rachis internodes 2–3 mm, silky villous. Spikelets 3–6 mm, purplish; callus hairs as long as spikelet; lower glume lanceolate, membranous, back glabrous or pilose with spreading hairs, keels scabrid, apex attenuate, minutely notched; lower lemma 3/4 as long to subequaling glumes; upper lemma elliptic, apex acute, awned; awn almost straight, 4–8 mm. Anthers 3, 2.1–2.2 mm. Fl. and fr. autumn. 2n = 20, 60.

Sandy places; 1200–3000 m. Xinjiang [Afghanistan, NW India, Kazakhstan, Kyrgyzstan, Pakistan, Tajikstan, Turkmenistan, Uzbekistan; SW Asia, S Europe; introduced in America].

This is a polymorphic species showing much variability in the disposition of hairs on the glumes. Sometimes the spikelets are slightly dimorphic, with the sessile spikelet almost glabrous and the pedicelled one strongly pilose. This species has a more profusely branched panicle with shorter racemes than others in China.

The stout clumps are useful in erosion control. This grass is also used for forage when young.