Serrated tussock (Nassella trichotoma) is a highly invasive, unpalatable, tussock-forming perennial grass. It produces large quantities of seed that easily outcompete and dominate pastures and native grass ecosystems.
- grows to a height of 600mm
- leaves are approximately 0.5mm in diameter and tightly rolled, appearing circular in cross-section
- noticeable serrations can be felt when running fingers from top to bottom of leaves
- small white hairless flap (ligule), approximately 1mm long, protruding vertically at the junction of the leaf and the leaf sheath
- flowering stems are multi branched, initially erect up to 950mm long, drooping at maturity to touch the ground.
Why is it a problem?
- competes with desirable pasture plants
- dense infestations can totally dominate pastures, rendering large areas incapable of supporting livestock
- unpalatable or indigestible with no grazing value
- control programs can be expensive and time consuming
- reduces biodiversity in native vegetation
- fire risk.
- does not occur wild in South Australia, but is naturalised in Victoria, New South Wales and Tasmania.
- produces up to 100,000 seeds that can remain viable in the soil for years
- can flower throughout the year, but main flowering period occurs from spring (October) to summer (January)
- affects non-arable grazing, native vegetation and crops or pastures
- lives for up to 20 years.
How it spreads
- spread by seed, primarily dispersed by wind
- seed heads break of at the base of the plant and can blow up to 20km
- seeds catch on bodies and hooves of animals
- known to remain viable for 10 days in the stomach of grazing animals
- seed can also be spread via machinery, clothing, hay and firewood.