4. Gastrochilus calceolaris (Buchanan-Hamilton ex Smith) D. Don, Prodr. Fl. Nepal. 32. 1825.
盆距兰 pen ju lan
Aerides calceolaris Buchanan-Hamilton ex Smith in Rees, Cycl. 39: Aerides no. 11. 1818; Saccolabium calceolare (Buchanan-Hamilton ex Smith) Lindley.
Stems often arching, 5-30 cm, 5-8 mm in diam., with many leaves. Leaves distichous; blade often falcate, narrowly oblong, 20-23 × 1.5-2.5 cm, slightly fleshy, apex obtuse and unequally 2-lobed. Inflorescences several to many, from upper part of stem, opposite to leaves, subumbellate, 2-3 cm, several to many flowered; floral bracts small; pedicel and ovary slightly compressed, 1.3-2 cm. Flowers widely opening; sepals and petals yellow, with purplish brown markings; lip with white epichile and yellow hypochile, both with purple-red marks. Sepals similar, obovate-oblong, 7-8 × ca. 4 mm, base contracted, apex obtuse-rounded. Petals similar to sepals, slightly smaller, apex obtuse-rounded; lip with an epichile and a saccate hypochile; epichile spreading forward, suborbicular-triangular or lunate-triangular, 2-3 × 5-7 mm, adaxially with long white hairs except on yellow and purple-spotted central cushion and with a cavity at base of cushion, margin irregularly fimbriate or erose; hypochile yellowish green with purplish red margin, helmetlike, ca. 5 mm tall, ca. 5 mm in diam. Fl. Mar-Apr. 2n = 38, 40, 76.
On tree trunks in forests; 1000-2700 m. Hainan, S Xizang, S and W Yunnan [Bhutan, NE India, Malaysia (Peninsular), Myanmar, Nepal, Thailand, Vietnam].