[3][4] It is a perennial plant that is densely branched and bushy, about 400 mm high.

A line of rounded pearl-like hairs on the margins gives leaves a silvery edge.

There are also small hairs that point downwards on the immature stems that feature a silvery tinge.

The flowers are sorted in cloaked clusters, jammed at the branches' ends, with nectar that exudes a distinguishing scent.

[3] Crassula undulata grows on south or south-west facing slopes or in gorges, rock outcrops, ledges or rock crannies in the Riviersonderend Mountains adjacent to Stellenbosch in South Africa's Western Cape, which is northwards from the Cederberg mountains.