Plants lithophytic. Leaves 4-6, distichous, spreading horizontally; blade abaxially pale green and carinate, adaxially uniformly deep green and glossy, narrowly oblong, 12-28 × 3.5-5.9 cm, leathery, basal margin purple ciliate, apex obtuse. Scape suberect or slightly arching, terminating in a solitary flower; peduncle yellowish green with purple speckles, 8-20 cm, densely white pubescent; floral bract yellowish green with purplish speckles, ovate-elliptic, conduplicate, 4.5-6 cm, abaxially puberulent, ciliate; pedicel and ovary green with purplish speckles, 3-4.5 cm, densely puberulent. Flower scented, 11-14 cm in diam., yellowish, obscurely with greenish reticulate veins, flushed with purple toward base of petals, with dense purple spots at inner bottom of lip and many purple irregular transverse stripes or net on adaxial surface of staminode. Dorsal sepal suberect to curving forward over lip, broadly ovate-elliptic or elliptic, 4.8-6.2 × 3-4.6 cm, both surfaces puberulent, abaxially carinate, minutely ciliate, acute at apex; synsepal broadly elliptic, 4.8-6.4 × 3.6-5.7 cm, both surfaces puberulent, minutely ciliate, obtuse and slightly bilobulate at apex. Petals broadly obovate-elliptic, slightly oblique, 5.5-7.3 × 3.5-6.4 cm, both surfaces puberulent, adaxially densely white villous toward base, minutely ciliate; lip subglobose, 4-5 × ca. 3.4 cm, outside glabrous, apical margin involute. Staminode broadly obovate-triangular, 1.6-2.1 × 1.8-2.2 cm, abruptly narrowed at base into a claw, obtuse-rounded at apex. Fl. Apr-May.