The plant features numerous shiny brownish-gray-green warts that are curved, acutely triangular on one side, and sharply keeled backward to the base.

Its numerous yellowish flowers, up to 50 mm long and wide, form a wreath around the woolly crown.

[3][4] Ariocarpus trigonus is native to the Mexican states of Nuevo León and Tamaulipas.

It grows on flat limestone hilltops in coarse, sandy-gravelly soil at altitudes between 500 and 1200 meters.

First described as Anhalonium trigonum by Frédéric Albert Constantin Weber in 1893, the species was placed in the genus Ariocarpus by Karl Moritz Schumann in 1898.