Nassella tenuissima

Nassella tenuissima is a species of grass known by the common names Mexican feathergrass, finestem needlegrass, fineleaved nassella, and Argentine needle-grass. It is native to the south-western United States, northern Mexico and Argentina. It is well-matched to climate in Australia and can be harmful to the Australian environment.

It is still widely referenced in botanical and horticultural literature under its synonym Stipa tenuissima, and has received the Royal Horticultural Society's Award of Garden Merit under that name.