Dioon spinulosum (known as the giant Dioon) is one of the largest and easiest of all Cycad plants. Keep it as a pot plant on your terrace or indoors. As is the case with most Cycas, it grows slowly. It's a living fossil from the Mesozoic era, found in Mexican rain forests where it is threatened by limited habitat and destruction of woodland. The name spinulosum refers to the barbs along the leaves. It's recommended to handle the plant with protective gloves and to keep it in a place where people will not brush up against it!