Vernation

Vernation, in Botany, a term employed to designate the manner in which the leaves are arranged in the leaf-bud. It corresponds with Estivation (q.v.) in the flower-bud. There are great differences in the vernation of plants, which are characteristic not only of species but of genera, and even of natural orders; the vernation of the same species is always the same. In some plants the leaves are very simply placed together; in others they are most curiously folded, rolled, or plaited, and interlaced with each other, yet so as to separate most readily when the proper time for their expansion comes.