Latin rÄ•tÅ«sus ’rounded with a slightly notched tip’. For the shape of the tips of the tubercles (Scheidweiler: “foliis [sic] multifariis deltoïdeis apice retusis”). Anderson (in Amer. J. Bot. 51(2): 145. 1964) claims “[t]he specific epithet retusus was chosen by Scheidweiler because of the similarity of the tubercles to the leaves of the commonly cultivated Aloë retusa [= Haworthia retusa]”. This could very well be true, but is not mentioned by Scheidweiler. Lemaire, who described the same species as Anhalonium prismaticum, did note that “the habit is entirely that of certain Aloes (A. retus[a])”.
Ariocarpus retusus. Image credit: Amante Darmanin / CC BY 2.0Haworthia retusa. Image credit: Abu Shawka / CC BY-SA 4.0
Maarten H.J. van der Meer (2023 Dec 09). Ariocarpus retusus. Dictionary of Cactus Names. Retrieved from https://www.cactusnames.org/ariocarpus-retusus