only species currently recognised in this genus is Fenestraria rhopalophylla. Each leaf has an epidermal window, a transparent window-like area, at its rounded tip, it is for these window-like structures that the genus is named (Latin: fenestra).

Fenestraria rhopalophylla appears very similar to Frithia pulchra, though the leaves are a slightly different shape and F. rhopalophylla has yellow flowers, compared