decussate

Fertile catkins globular, of shield-shaped scales decussate in pairs, bearing few (1–4) erect bottle-shaped ovules at base.

A Melaleuca with very small decussate leaves, a tree about twenty-five feet high, was growing on the scrubby ridges.

The whorls or pairs alternate or cross each other, usually at right angles, that is, they decussate.

The remaining fibres pass down as the direct pyramidal tract, and decussate in the cord near their termination.

Thus, leaves normally opposite and decussate may, by fusion, become alternate.