Used of opposite organs (e.g. leaves), when alternate pairs are at right angles to each other.
Having paired organs with successive pairs at right angles to give four rows.
In reverse pairs with the rotate pairs projecting at right angles to each other.
Opposite leaves that alternate at right angles to one another at successive nodes, thereby forming four rows of leaves.
A successive arrangement of pairs which cross each other.
With organs on opposite sides of a stem or other axis in which the pairs above each other are at right angles.
To cross, or crossed, as in the form of an X.