About Oreorchis patens (Lindl.) Lindl.
Oreorchis patens (Lindl.) Lindl. is a terrestrial, perennial herb that spreads via pseudobulbs. The pseudobulbs are egg-shaped, measuring 1–2 cm by 0.5–1.5 cm (0.39–0.79 in by 0.20–0.59 in), and bear 2 to 3 nodes that eventually develop into separate growths. Chains of these pseudobulbs are connected by a short rhizome. Leaves are typically solitary, though they rarely occur in pairs; they measure 13–30 cm (5.1–12 in) long and 1–2 cm (0.39–0.79 in) wide, and are linear or narrowly lanceolate with a pleated texture. Leaves taper gradually toward the base into an indistinct petiole-like stalk, and end in a pointed apex. The inflorescence grows 25–67 cm (9.8–26 in) tall, and holds 2 or 3 tubular sheaths below its midpoint. The rachis measures 4–15.5 cm (1.6–6.1 in), and can bear a lax arrangement of few flowers or a relatively dense arrangement of many flowers. Floral bracts are narrowly lanceolate, 2.5–5 mm (0.098–0.20 in) long. Flowers are yellowish brown to pale yellow, with a white lip that often has purple spots. Sepals are narrowly oblong, measuring 7–9 mm by 1.5–2 mm (0.28–0.35 in by 0.059–0.079 in), with slightly blunt apices. Lateral sepals are slightly sickle-shaped, and wider than the dorsal sepal. Petals are narrowly oblong, slightly curved, measuring 7–8 mm by 1.5–1.8 mm (0.28–0.31 in by 0.059–0.071 in), with pointed apices. Both sepals and petals have 3–5 veins. The lip is oval-shaped with a narrower base, measuring 6.5–8.5 mm by 3.5–5 mm (0.26–0.33 in by 0.14–0.20 in). It is tri-lobed and has a short claw at its base. The lip's lateral lobes are slightly incurved, linear, around 3 mm by 0.7 mm (0.12 in by 0.028 in), with blunt apices. The mid-lobe is oval-shaped, measuring 5.5–7 mm by 3–5.5 mm (0.22–0.28 in by 0.12–0.22 in), with a rounded apex and irregularly incised edge. The callus is formed of a pair of thick lamellae, which extend from the base to halfway along the mid-lobe. The column is 4–5 mm (0.16–0.20 in) long, with a thickened base. Combined pedicels and ovaries are 8–12 mm (0.31–0.47 in) long, and the capsule is oblong, around 15 mm long by 7 mm wide (0.59 in by 0.28 in). This species flowers from June to July, and its capsules ripen from September to October. The diploid chromosome number of Oreorchis patens is 2n = 48. This species, commonly called common oreorchis, is distributed across Japan, Korea, the Russian Far East (including Kamchatka, Primorye, Sakhalin, and the Kuril Islands), and China (found in Gansu, Guizhou, Heilongjiang, Henan, Hunan, Jiangxi, Jilin, Liaoning, Sichuan, Taiwan, and Yunnan). It grows in forests, forest margins, thickets, grassy areas, and shaded valley locations at elevations between 1,000 and 3,000 metres (3,300–9,800 ft). Two hoverfly species, Episyrphus balteatus and Sphaerophoria menthastri, are known pollinators of Oreorchis patens.
