Why be straight when you can be curly? Crassula Undulata is a unique, attention grabbing indoor succulent with delightful wavy blue-green leaves. Easy to care for, like many other Crassula the leaves have red margins, particularly in cooler temperatures. It is a small, compact hybrid, sometimes going under the name Crassula Curly. If left unpruned it will eventually form a small tree shape, with thickened stems and branches.