Description from Flora of China
Cyrtopera flava Lindley, Gen. Sp. Orchid. Pl. 189. 1833; C. cullenii Wight; Cyrtopodium flavum (Lindley) Bentham (1881), not Link & Otto ex Reichenbach (1830); Eulophia cullenii (Wight) Blume; Graphorkis flava (Lindley) Kuntze; Lissochilus flavus (Lindley) Schlechter.
Plants autotrophic, 60-95 cm tall. Pseudobulb borne above ground, erect, pale greenish, subcylindric, 4-5 × 1.5-2 cm, many noded, with a few roots. Leaves usually 2, usually emerging after anthesis, oblong-lanceolate, 25-35 × 4.5-6 cm, papery, tapering at base into a long petiole-like stalk, apex acuminate; petiole-like stalk ca. 16 cm, equitant and forming a pseudostem. Inflorescence usually arising from an upper node of pseudobulb, racemose, 60-95 cm, thick, with several scattered sheaths 4-8 cm; rachis 18-32 cm, laxly more than 10-flowered; floral bracts lanceolate, 15-25 mm, shorter than ovary, apex acute to acuminate. Flowers lemon-yellow with purple or crimson spots inside toward base, large, 40-50 mm in diam., not scented; pedicel and ovary 25-30 mm. Sepals similar, narrowly elliptic-lanceolate, 30-36 × 9-11 mm, apex acute or acuminate; lateral sepals oblique. Petals obovate-elliptic or subobovate, 23-28 × 12-15 mm, apex rounded; lip broadly ovate, 25-30 × 20-25 mm, saccate-spurred at base, 3-lobed; lateral lobes incurved and loosely embracing column, subovate, apex rounded; mid-lobe oblate to subquadrate, 6-11 × 10-13 mm; disk with 3 papillate ridges extending from near base of lip to base of mid-lobe; outer 2 ridges longer and dilated into suborbicular lamellae at middle of disk; spur a broad sac ca. 3 mm, apex rounded. Column 12-15 mm, without a column foot. Fl. Apr-Jun.
Crevices along streamsides, open grassy slopes; below 400 m. SW Guangxi, Hainan, Hong Kong [India, Laos, Myanmar, Nepal, Thailand, Vietnam].