线柱兰 xian zhu lan

Orchis strateumatica Linnaeus, Sp. Pl. 2: 943. 1753; Adenostylis emarginata Blume; A. integerrima Blume; A. strateumatica (Linnaeus) Ames; A. sulcata (Roxburgh) Hayata; Neottia strateumatica (Linnaeus) R. Brown; Pterygodium sulcatum Roxburgh; Spiranthes strateumatica (Linnaeus) Lindley; Tripleura pallida Lindley; Zeuxine bonii Gagnepain; Z. bracteata Wight; Z. brevifolia Wight; Z. emarginata (Blume) Lindley; Z. integerrima (Blume) Lindley; Z. procumbens Blume; Z. robusta Wight; Z. rupicola Fukuyama; Z. stenochila Schlechter; Z. strateumatica f. rupicola (Fukuyama) T. Hashimoto; Z. strateumatica var. rupicola (Fukuyama) S. S. Ying; Z. sulcata (Roxburgh) Lindley; Z. tripleura Lindley; Z. wariana Schlechter.

Plants 4-24 cm tall, slender. Rhizome short. Stem erect or ascending, pale brown, with several to many leaves. Leaves cauline, usually clustered and overlapping, pale brown, linear to linear-lanceolate, sometimes bractlike, 2-8 × 0.2-0.6 cm, base directly sheathing stem, not stalked, apex acuminate. Inflorescence 2-7 cm, glabrous, with a few to more than 20 densely arranged flowers; floral bracts reddish brown, ovate-lanceolate, 8-12 mm, longer than flower, glabrous, apex long acuminate. Flowers resupinate, white or yellowish white, small; ovary and pedicel elliptic-cylindric, 5-6 mm, glabrous. Sepals glabrous; dorsal sepal narrowly ovate-oblong, concave, 4-6 × 2-3 mm, 1-veined, apex obtuse; lateral sepals obliquely oblong, 4-5.5 × 1.5-2.5 mm, 1-veined, apex acute or obtuse. Petals subovate to obovate, oblique, 4-5.5 × 1.5-1.8 mm, glabrous, 1-veined, apex obtuse; lip pale yellow to yellow, cymbiform, 4-5 mm, 3-partite; hypochile concave-saccate, containing 2 subtriangular, lamellate calli; mesochile ca. 1 mm, exterior surfaces minutely papillate toward apex, margin denticulate, involute; epichile transversely elliptic-oblong, 1.4-1.8 × 2-2.5 mm, minutely papillate, apex with a small mucro to slightly emarginate. Column ca. 1.5 mm; wings longitudinally oblong; rostellum arms ca. 0.6 mm. Capsule pale brown, elliptic, ca. 6 mm. Fl. Mar-Jul. 2n = 20, 22, 40, 42, 50, 100.

Damp grasslands, meadows, valleys, along streams; below 1000 m. Fujian, Guangdong, Guangxi, Hainan, Hubei, Sichuan, Taiwan, Yunnan [Afghanistan, Bhutan, Cambodia, India, Japan, Kashmir, Laos, Malaysia, Myanmar, New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; SW Asia, Pacific islands].

This is a weed in Saudi Arabia and the United States (Florida, Hawaii).