Any of various coarse, tussock-forming grasses constituting the genus Nassella, native to the Andes; specifically the Chilean N. trichotoma, which was introduced to parts of New Zealand and South Africa and has locally established itself there as a troublesome weed. Also (in form Nassella): the genus itself.
Valid publication of the genus name: E. E. Desvaux in C. Gay Historia Física y Política de Chile, Botánica (1853) VI. 263.
Early 20th century; earliest use found in Bulletin of the Torrey Botanical Club. From scientific Latin Nassella from classical Latin nassa + -ella.