4. Chrysopogon aciculatus (Retzius) Trinius, Fund. Agrost. 188. 1820.
竹节草 zhu jie cao
Andropogon aciculatus Retzius, Observ. Bot. 5: 22. 1789; Centrophorum chinense Trinius.
Perennial with extensively creeping rhizomes, sward forming; rhizomes stout, close-noded. Culms decumbent at base or ascending, 20–50 cm tall. Leaf sheaths glabrous or ciliate at mouth; leaf blades broadly linear, 3–5 × 0.4–0.6 cm, glabrous or adaxial surface pilose near base, margins serrate, apex subacute; ligule 0.1–0.3 mm. Panicle dense, oblong in outline, 5–9 cm, purplish brown; branches erect when dry, 1.5–3 cm, tipped by a single triad. Sessile spikelet 3.5–4 mm; callus acicular, 4–6 mm, bearded with golden hairs, obliquely attached to branch apex; glumes leathery; lower glume lanceolate, 2-keeled upward, lower back smooth, glabrous, upper back thinner, keels hispidulous, apex acute to 2-toothed; upper glume setulose on upper keel, acuminate or mucronate, mucro 1–2 mm; upper lemma entire, awned; awn straight, 4–7 mm. Pedicelled spikelet staminate, 4–5.7 mm; lower glume acuminate or with mucro to 1 mm. Pedicel 3/4 length of sessile spikelet, glabrous. Fl. and fr. Jun–Oct. 2n = 20.
Dry open grasslands, waste ground, lawns; 500–1000 m. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Taiwan, Yunnan [Afghanistan, Bangladesh, Bhutan, Cambodia, India, Indonesia, Malaysia, Myanmar, Nepal, Pakistan, Philippines, Singapore, Sri Lanka, Thailand, Vietnam; Australia, Pacific Islands (Polynesia)].
Rarely, racemes of this species may have one or more spikelet pairs below the triad.
This is a ground-cover grass used for erosion control and lawns. It sometimes becomes a noxious weed. The needle-sharp callus on the diaspore can injure cattle and other animals, catching in fur and then penetrating the skin.