Nassella trichotoma, the serrated tussock, is a type of bunchgrass plant, native in Argentina, Uruguay, Chile, and Peru.

It is on the list of Weeds of National Significance in Australia, reducing the productivity of pasture and creating a fire hazard. In many states, landowners are required by law to keep their land free of this plant.

In New Zealand is classed as an unwanted organism by Biosecurity New Zealand and is under strict control regimes by some of the regional councils.