Small, tubular green-and-white flowers are produced on spikes rising from the clump of fat green leaves with translucent windows at their tips in midwinter. The windows are created by the absence of chlorophyll in each of the three layers of cells. In the wild, leaves recurve to create a flat surface matching the surrounding soils; in the lower light levels of homes, they frequently lose this characteristic.

This plant is very closely related to the genera Gasteria and Aloe, which are also from South Africa.