× Gasteraloe hybrids are typically stemless or almost stemless. Their succulent leaves, which are usually spotted or marked and have toothed margins, form rosettes.
Gonialoe variegata and Aristaloe aristata are especially commonly used for these hybrids, as they are far more amenable to hybridization with gasterias than most other "aloes".
View source for more information: https://en.wikipedia.org/wiki/%C3%97_Gasteraloe