the prickly ash genus of the rue family ( Rutaceae), comprising about 200 species of aromatic trees and shrubs native to the middle latitudes of North America, South America, Africa, Asia, and Australia. There are both deciduous and evergreen species. They have small, greenish flowers and fruits that consist of groups of two-valved capsules, each containing a single shiny black seed.

Common prickly ash, or toothache tree (Z. americanum), is very hardy, appearing as far north as Quebec. Another well-known cultivated species is Z. clava-herculis, variously called the Hercules'-club, the sea ash, or the pepperwood. West Indian satinwood, or yellowheart (Z. flavum), produces shiny, golden-brown timber for cabinetwork.