Agave ( or ) is a genus of monocots. The plants are perennial, but each rosette flowers once and then dies (see semelparity). Some species are known by the name century plant. In the APG III system, the genus is placed in the subfamily Agavoideae of the broadly circumscribed family Asparagaceae. Some authors prefer to place it in the segregate family Agavaceae. Traditionally, it was circumscribed to be composed of about 166 species, but it is now usually understood to have about 208 species.