Smilax is a genus of about 300–350 species, found in the tropics and subtropics worldwide. They are climbing flowering plants, many of which are woody and/or thorny, in the monocotyledon family Smilacaceae, native throughout the tropical and subtropical regions of the world. Common names include catbriers, greenbriers, prickly-ivys and smilaxes. Sarsaparilla is a name used specifically for the Neotropical S. ornata as well as a catch-all term in particular for American species. Occasionally, the non-woody species such as the smooth herbaceous greenbrier are separated as genus Nemexia; they are commonly known by the rather ambiguous name carrion flowers.

Monocotyledons, commonly referred to as monocots, are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of the major groups into which the flowering plants have traditionally been divided; the rest of the flowering plants have two cotyledons and are classified as dicotyledons, or dicots.