What is "agave atrovirens"

Maguey \Mag"uey\, n. [Sp. maguey, Mexican maguei and metl.] (Bot.) Any of several species of Agave, such as the century plant ( Agave Americana), a plant requiring many years to come to maturity and blossoming only once before dying; and the Agave atrovirens, a Mexican plant used especially for making pulque, the source of the colorless Mexican liquor mescal; and the cantala ( Agave cantala), a Philippine plant yielding a hard fibre used in making coarse twine. See Agave.

2. A hard fibre used in making coarse twine, derived from the Philippine Agave cantala ( Agave cantala); also called cantala.