5. Amitostigma monanthum (Finet) Schlechter, Repert. Spec. Nov. Regni Veg. Beih. 4: 94. 1919.
一花无柱兰 yi hua wu zhu lan
Peristylus monanthus Finet, Rev. Gén. Bot. 13: 523. 1901; Amitostigma forrestii Schlechter; A. monanthum var. forrestii (Schlechter) Tang & F. T. Wang; A. nivale Schlechter; Orchis forrestii (Schlechter) Soó; O. monantha (Finet) Soó; O. nivalis (Schlechter) Soó.
Plants 6-10 cm tall. Tubers ovoid to subglobose, ca. 5 mm in diam. Stem with 1 or 2 tubular sheaths at base, 1-leaved, occasionally pubescent. Leaf basal, erect to porrect, lanceolate, narrowly oblong, or oblanceolate-spatulate, 2-3 × 0.6-1 cm, apex acute or obtuse. Peduncle ebracteate; rachis 1-flowered; floral bract linear-lanceolate, 6-12 mm, usually exceeding ovary, apex acute. Flower pale purple, pink, or pure white, with purple spots on lip, rather large; ovary and pedicel 6-11 mm. Dorsal sepal erect, narrowly ovate, concave, 4-4.5 × 1.6-1.8 mm, 1-veined, apex obtuse; lateral sepals spreading to reflexed, narrowly oblong-elliptic, 4.5-5 × ca. 1.6 mm, apex subobtuse. Petals loosely connivent with dorsal sepal and forming a hood, ovate, slightly oblique, 3.8-4.4 × 1.6-2 mm, 1-veined, apex obtuse; lip ovate-orbicular, 8-10 × 8-10 mm, base shortly clawed, deeply 3-lobed below middle; disk finely papillate; lateral lobes suboblong-obovate, 4-5 × 1.8-3 mm, margin often slightly undulate, apex obtuse; mid-lobe broadly obovate, 6-7.5 × ca. 7 mm, much wider than lateral lobes, margin usually entire or sometimes slightly undulate, apex slightly emarginate to deeply notched to form 2 distinct lobules; spur pendulous, straight, cylindric, 2.5-4 mm, much shorter than ovary, apex obtuse; viscidia ovate; stigma lobes subsquare. Fl. Jul-Aug.
● Grassy slopes, alpine meadows, rocky soils and gravel along streams; 2800-4100 m. S Gansu, S Shaanxi, NW and W Sichuan, SE Xizang, NW Yunnan.