Philodendron callosum is found in Venezuela, the Guiana Shield, and northwestern Brazil, P. callosum is largely found as an epiphytic species growing on dead trees. epiphytes (ep-a-FIT) are those plant species that grow attached to another plant, in most cases a tree. But the epiphytic Philodendron callosum is botanically in a section of species that commonly grow on the ground and even on stone.  That Philodendron section is Philiopsammos.