A monocotyledon, climbing plant with hooked thorns, of the genus Smilax (family Smilaceae), that will grow over small trees and shrubs, but also occurs as a shrub, with heart-shaped leaves, and fruits that are berries. Extracts from the roots of some species is used to make the root beer sarsaparilla. There are 315 species occurring throughout the tropics and warm temperate regions.