Malaxis monophyllos (Linnaeus) Swartz, Kongl. Vetensk. Acad. Nya Handl. 21: 234. 1800.

原沼兰 yuan zhao lan

Ophrys monophyllos Linnaeus, Sp. Pl. 2: 947. 1753; Achroanthes monophylla (Linnaeus) Greene; Epipactis monophylla (Linnaeus) F. W. Schmidt; Malaxis arisanensis (Hayata) S. Y. Hu; M. muscifera (Lindley) Kuntze var. stelostachya Tang & F. T. Wang; M. taiwaniana S. S. Ying; M. yunnanensis (Schlechter) Tang & F. T. Wang; M. yunnanensis var. nematophylla Tang & F. T. Wang; Microstylis arisanensis Hayata; M. monophyllos (Linnaeus) Lindley; M. yunnanensis Schlechter.

Plants terrestrial. Pseudobulbs ovoid, relatively small, usually 6-8 × 4-5 mm, ± enclosed in white membranous sheaths. Leaf 1 or rarely 2, ovate, oblong, or subelliptic, 2.5-7.5(-12) × 1-3(-6.5) cm, base contracted into ± amplexicaul petiole 3-6.5(-8) cm, apex obtuse or subacute. Inflorescence erect, (9-)15-40 cm, many flowered; rachis 4-12(-20) cm, narrowly winged; floral bracts 2-2.5 mm, lanceolate. Flowers pale yellowish green to pale green, small; pedicel and ovary 2.5-4(-6) mm. Dorsal sepal lanceolate or narrowly ovate-lanceolate, 2-4 × 0.8-1.4 mm, 1-veined, apex long acuminate; lateral sepals linear-lanceolate, 2-4 × 0.7-1.2 mm, 1-veined. Petals filiform or narrowly lanceolate, 1.5-3.5 × ca. 0.3 mm; lip ovate-triangular, 3-4 mm, caudate; disk broadly ovate or oblate, slightly concave, margin thickened and verrucose, base with a pair of short auricles on each side. Column ca. 0.5 mm, stout. Capsule obovoid or obovoid-ellipsoid, 6-7 × ca. 4 mm; fruiting pedicel 2.5-3 mm. Fl. and fr. Jul-Aug. 2n = 28, 30, 60.

Forests, thickets, grassy slopes; 800-2400 m (2500-4100 m in NW Yunnan and Xizang). Gansu, Hebei, Heilongjiang, Henan, Hubei, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi, Sichuan, Taiwan, Xizang, W Yunnan [Japan, Korea, Russia; Europe, North America].