Serrated tussock [(Nassella trichotoma (Nees) Hack. # STDTR] is a clump-forming, perennial, cool season grass. It is native to South America, where it occurs in Argentina, Brazil, Chile, Peru, and Uruguay. In the past century, it has been introduced to New Zealand, Australia and South Africa, and also occurs in small acreages in France, Italy, and the United Kingdom. Serrated tussock occurs in fields, wastelands, and pastures, but rarely in wet or shaded areas.