Leaf arrangement (phyllotaxy)

Flora of Australia Glossary — Vascular Plants

Compiled by A. McCusker


Leaf arrangement (phyllotaxy)

alternate: of leaves or other lateral organs, borne singly at different heights on the axis; of floral parts, on a different radius, e.g. describing the position of stamens with respect to petals. cf. opposite.

distichous: arranged in two rows on opposite sides of a stem and thus in the same plane.

opposite: of leaves or other lateral organs, borne at the same level but on opposite sides of the stem; of floral parts, on the same radius. cf. alternate.

phyllotaxy: the arrangement of leaves on a stem (when spiral, often expressed quantitatively as the fraction of the circumference of the stem that separates two successive leaves).

verticillate: arranged in one or more whorls; a false whorl of flowers in a pair of opposite dense cymes, especially in Lamiaceae.

whorl: a ring of leaves, bracts or floral parts borne at the same level on an axis. cf. cyclic, spiral.