A key to the genus Calyptrochilum Kraenzl.

1a. Inflorescence many-flowered, very dense, up to 5 cm. long, bracts closely imbricate, middle ones 4-7 mm. long; leaves 6-17 cm. long, 2.5-5 cm. broad; lip obscurely 3-lobed in front, side lobes broadly rounded, middle lobe much smaller, acute; sepals about 1 cm. long; lip including spur 2 cm. long. Calyptrochilum emarginatum
1b. Inflorescence usually 6-9-, sometimes up to 12-flowered, rather lax, up to 4 cm. long, bracts not imbricate, middle ones 2-4 mm. long, rhachis more or less zigzag; leaves 3-13 cm. long, 0•8-2•5 cm. broad; lip distinctly 3-lobed, lobes rounded, middle lobe much larger and longer than side lobes, emarginate; sepals 6-8 mm. long; lip including spur 1-8 cm. long. Calyptrochilum christyanum

World Checklist of Monocotyledons. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; accessed 24/02/2017