Nassella trichotoma, Serrated Tussock

Grasses and Sedges
Scientific Name
Nassella trichotoma
Common Name/s
Serrated Tussock
Weed Information

Status: Declared Noxious Weed (Regionally Controlled), Weed of National Significance.

Threat: High threat environmental and agricultural weed.

Description: A perennial tussock grass up to 50cm tall and up to 25cm wide with deep fibrous root system and a branched flower head in early summer with small spear-like seeds, giving a distinct bleached, fluffy look.

Flowers and seeds: The small seeds are enclosed by dark purple glumes. Seed heads break off at maturity and are spread by wind. Flowers October to December.

Leaves and stems: Leaves very tightly rolled and cylindrical, rough to the touch, mid to yellow green and arranged in a dense tuft arising from the base of the plant. Tips of the leaves can appear bleached with age. Flowering stems are erect at first, but become droopy and brittle as the seeds develop.

Note: Unpalatable to stock and rabbits, invasive, drought and fire tolerant, and a prolific seeder (approx. 100,000 seeds per plant).

Similar indigenous species: Can be confused with native spear grasses (Austrostipa spp.) or native tussock grasses (Poa spp.). Spear grasses have centrally attached awns with no membranous collar and their leaf cross-section is flat or u-shaped. Native tussock grasses have awnless seeds, seed heads are usually retained for some months and leaf cross-section is flat or v-shaped.

Control measures: Hand weeding, spot spraying, slashing and mowing

Dispersal: Wind, animal, machinery, seeds.