Adromischus maximus, the largest member of the Adromischus genus, is a robust, perennial succulent reaching heights of about 20 cm. The plant has fibrous roots. Some stem branching occurs, stems being either erect or decumbent.
The distribution of the species lies in the Northern and Western Cape, in southern Namaqualand and southwards to the Gifberg. The plant grows on semi-arid shale slopes among sparse scrub; this region receives winter rain although not much. This Kirstenbosch specimen had a nearly flowered out, many-flowered inflorescence late in April (JSTOR; iSpot; Bond and Goldblatt, 1984).