Leafless achlorophyllose saprophytic herbs, with globose to narrowly cylindrical tubers. Stems erect, unbranched, slender, weakly flexuous. Inflorescences racemose, terminal, 1–many-flowered. Flowers small, fugacious, unspurred, yellow or brown. Tepals partially adnate, forming a short tube. Lip free, simple, with slender claw. Column elongated, scarcely widened at apex, arms and foot absent; anther declinate; pollinia 4; caudicle and viscid disc absent; stigma near apex of column. Pedicel lengthening considerably as erect capsule matures.
Terrestrial, saprophytic (obligate holomycotrophic), achlorophyllous herbs. Rhizome fleshy-tuberous, oblong or fusiform, gradually narrowed to apex. Stem erect, with a few sheaths near base. Leaves scale-like. Inflorescence erect, the rachis congested. Flowers patent, resupinate, frequently ephemeral, the sepals and petals pale brown to greenish brown, labellum pale white, sometimes with faint yellow markings through proximal half. Sepals dissimilar, dorsal sepal free, broadly spreading, more or less ligulate, lateral sepals connate along their ventral margins for most of their length, weakly spreading, abruptly deflexed distally, slightly broader than dorsal sepal, hardly or not dilated ventrally at base. Petals free, broadly spreading to patent, similar in size and shape to dorsal sepal. Labellum joined to base of column, free from and broader than other perianth parts, entire or weakly bilobed, unspurred, base clawed, disc with a pair of yellow calli at base, regions above base naked. Column winged distally, broadened at top, with a pair of stelidia at apex, foot absent; anther incumbent, blunt at apex, pollinia four, granular, ecaudiculate; stigma directly below rostellum, sunken, viscidium distinctly bilobed, creating a V-shaped scar on anterior margin of rostellum when removed, rostellum erect, transverse. Capsule borne on an erect pedicel that elongates during maturation. (PK, MM).
Auxopus species are found in seasonally dry deciduous forest growing in accumulations of leaf litter. Two of the species, A. madagascariensis Schltr. and A. kamerunensis Schltr., are reported to flower in January. At least one species is reported to occur most frequently at localities with an underlying limestone substrate (Du Puy et al. 1999). (PK, MM).