This member of the Anacardiaceae family was described by Urs Eggli in 1995. It is found in a small area outside Toliara. It prefer a well drained soil, some water and lots of sun. The stem, or actually; caudex will grow from fifteen to 50 centimetres in diameter, the whole plant will reach one meter in height. The flowers are yellowish green.
The genera name from Latin operculum; 'little lid' and Greek karyum; 'nut', referring to the lidded, nut-like seeds. The species name from Greek pachys; 'thick' and Greek pous; 'foot'. A. Randrianasolo & P. P. Lowry, 2006: "This species most closely resembles (and is often confused with) O. decaryi, but can readily be distinguished by the distinctive zig-zag pattern of its branches". Male flower by Ferdinand Poilodan.

