Fauns and dryads are members of the same forest-dwelling species. Fauns are the males and dryads the females. The species has no name, since humans have traditionally treated the two genders as separate, and they simply call themselves 'the People'.
Dryads are born in an acorn, from which they hatch to reveal a creature that looks like a human baby, only much smaller. Within a few weeks they are the same size as a human baby. Fauns are also born very small and rapidly grow to human size. At puberty fauns develop hairy legs and horns, and dryads the power to change into trees (although cutting the bark will bring forth blood, not sap).