:: Ariocarpus retusus ssp trigonus -- The Ariocarpus retusus ssp trigonus may be found in several areas in the state of Tamaulipas and Nuevo Leon (close to the Aramberri region).

Being a retusus sub-species, the trigonus ssp may reach up to 30 cm in diameter.  Variations exist in tubercles size and shape, with some plants exhibiting long and thin tubercles whilst other have a rather short and broad appearance.  Furthermore, the ssp trigonus' tubercles are smooth and curve inwards.  The Ariocarpus retusus ssp trigonus produces large yellow flowers. ::

Ariocarpus retusus ssp trigonus