Serrated tussock can often be easily confused with other tussock-like grasses, both introduced and native.
Serrated tussock is one of seven Nassella grasses that occur in Australia. Others include Chilean needle grass (N. nessiana), Mexican feather grass (N. tenuissima), cane needle grass (N. hyalina), Texas needle grass (N. leucotricha), lobed needle grass (N. charruana) and short-spined needle grass (N. megapotamia).
Other Nassella species can be differentiated by seed size or the corona around the seed. To distinguish the seed of serrated tussock, compare the illustrations below.
Nassella species can be differentiated clearly through their seed heads. - Source: Enid Mayfield (Serrated Tussock Best Practice Manual).
Mexican feather grass (Nassella tenuissima)
Mexican feather grass is a tufted perennial grass growng to 70cm high.
The seed of Mexican feather grass is a similar size to serrated tussock (2 – 4mm long), with a longer awn (50 – 90mm) that is attached centrally to the seed. The awn of a serrated tussock seed is attached to the seed off centre. The awns may have several bends giving a ‘curly’ or ‘feathery’ appearance.
Mexican feather grass can be differentiated from serrated tussock via the difference their awns. - Source: DEPI Victoria
Texas needle grass (Nassella leucotricha)
Texas needle grass grows to 1 – 1.5m high. The leaves are 30cm long and 5mm wide, appearing flat or slightly inrolled. The corona of Texas needle grass has long (3mm) thin hairs. The seed is 6 – 10mm long and the awn is 35 – 60mm long and bent twice.
Texas needle grass can grow a lot taller than serrated tussock. - Source: DEPI Victoria
Cane needle grass (Nassella hyalina)
Cane needle grass is a perennial tussock forming grass. It has a larger seed than serrated tussock (3.5 – 6mm) with a corona with long thin hairs.
Cane needle grass is another tussock forming grass that can be mistaken for serrated tussock. - Source: Mandy Coulson
Chilean needle grass (Nassella nessiana)
Chilean needle grass forms erect, robust tussocks that can be up to one metre tall. The plants have a distinctive colour being a darker green during early growth stages compared to other pasture species and throughout winter can turn yellow due to frosts unlike other native species.
Chilean needle grass has a crown-like carona with thick, tooth-like hairs (less than 1.5mm), long panicle seed 6 – 10mm and awns 45 – 80mm long.
Chilean needle grass has a distinctly purple seed head. - Source: DEPI Victoria
Lobed needle grass (Nassella charruana)
The lobed needle grass plant forms a tussock 25 – 80cm high. The plant is persistently erect, even after mowing or grazing. When in flower, lobed needle grass can shimmer from a distance.
Lobed needle grass has a 4 – 6mm long whitish, papery corona, which can be teased apart to reveal two distinct lobes. The seed is 8mm long and slender.
Lobed needle grass has a distinctly longer seed head than serrated tussock and a large papery corona. - Source: DEPI Victoria
Lobed needle grass can look like it is shimmering in the sunlight. - Source: DEPI Victoria
Serrated tussock is very similar in appearance to many native grasses, including tussock grass (Poa labillardieri), snowgrass (Poa sieberiana), spear grass (Austrostipa spp.) and wallaby grass (Austrodanthonia spp.). Use the diagram below to help determine whether the plant is serrated tussock or a serrated tussock look-a-like.
Source: Linda Ayres 2008 (Serrated Tussock Best Practice Manual)
Wallaby grass (Austrodanthonia spp.)
The leaf blade of wallaby grass is folded in the bud and there are parallel veins of thickening on the leaf blade. Wallaby grass grows all year, has fine leaves, hairy ligules and a fluffy appearing seed head at maturity.
Wallaby grass remains green all year and grows 30-80cm tall. - Source: Native Seeds Pty Ltd.
Native (Silver) tussock (Poa labillardieri)
The seed heads of silver tussock are open and pyramid shape. The leaf blade is channelled and the plant grows on lower slopes and valley floors.
Silver tussock has an open, pyramid shaped seed head. - Source: Roger MacRaild
Kangaroo grass (Themeda triandra)
Kangaroo grass has leaf blades folded in the bud with old leaves having a red/brown tinge. The seeds are a shiny dark brown colour with a sharp base of collar hairs. Seed heads are 30 – 50cm long, red rusty in colour during summer and on stems with dark nodes.
Kangaroo grass is an erect tufted perennial growing up to 150cm tall and 50cm wide. - Source: Native Seeds Pty Ltd.
Native Stipa and Austrostipa spp.
Spear grass or Austrostipa is a coarse tufted grass that remains green all year. The leaves are rough to touch and covered in miniature hairs. The seed has a long awn with a corkscrew twist up to six centimetres long.
Austrostipa seeds have a long awn with a corkscrew twist. - Source: Roger MacRaild