Tongue orchids are terrestrial herbs with one to a few stalked leaves at the base of the flowering stem, or leafless.

Orchids in the genus Cryptostylis are terrestrial, perennial herbs with a thick, branching underground rhizome with vertical shoots forming at nodes.

[2][3] Cryptostylis was first formally described in 1810 by the prolific Scottish botanist, Robert Brown and the description was published in his book, Prodromus Florae Novae Hollandiae et Insulae Van Diemen.

[6] The genus comprises around twenty five species of terrestrial orchid distributed from India, Sri Lanka, Thailand, Taiwan, the Philippines, and Malaysia through Indonesia to Australia and New Zealand, as well as Samoa, New Caledonia and Vanuatu.

The mimicking of flowers to resemble female wasp parts has since been recorded in other orchid genera but only in Cryptostylis has the insect been observed ejecting seminal fluid containing sperm cells.

[2][8][9] The flowers of Cryptostylis orchids and female wasp body parts are very similar in colour when viewed under a hymenopteran visual system, despite looking different to human eyes.

Furthermore, gas chromatography and electrophysiology show that the single active compound for pollinator attraction is found in different species of Cryptostylis.