Callisia and Tradescantia are actually terms for two genera that belong to the Commelinaceae family. Therefore, the species in these two genera are completely different. The most common plant from the Callisia genus is Callisia repens aka turtle vine. Tradescantia zebrina is the most common species in the Tradescantia genus. Another common plant from this family is Geogenanthus Ciliatus. Both plants have similar plant care requirements and will make excellent houseplants.