See here Conophytum is a genus of South African and Namibian succulent plants that belong to the family Aizoaceae.

Each leaf pair (together referred to as a body) ranges in shape from "bilobed" to spherical to ovoid to tubular to conical.

To the naked eye the epidermis ranges from very smooth to slightly rough to hairy, depending on the microscopic epidermal cell shape and structure.

When very heavy rains come to their native habitat they may grow luxuriantly and develop two leaf pairs per stem simultaneously; this is called "stacking up" of the leaves.

However, this was too tentative to establish a validly published generic name and also, Haworth himself neither adopted it nor accepted the genus.