foliate

To split into thin layers or leaves — as certain rocks do along planes of weakness, peeling apart like the pages of a book. Slate foliates. Mica foliates. Phyllosilicate minerals define their identity by foliation. In botany, to foliate is to produce leaves, to leaf out, to turn a bare branch into a living surface. Both senses share the same image: something flat, layered, multiplied.