What is "phyllotaxis"

Phyllotaxy \Phyl"lo*tax`y\, Phyllotaxis \Phyl"lo*tax`is\, n. [Phyllo- + Gr. ta`xis order.] (Bot.) The order or arrangement of leaves on the stem; the science of the relative position of leaves.

n. (context botany English) The arrangement of leaf on a stem, or the mathematical principles governing such arrangement.

In botany, phyllotaxis or phyllotaxy is the arrangement of leaves on a plant stem (from Ancient Greek phýllon "leaf" and táxis "arrangement"). Phyllotactic spirals form a distinctive class of patterns in nature.