Pest plant - Chilean and Texas needle grass
- Fact sheet
- August 2015
Chilean and Texas needle grass (Nassella neesiana and Nassella leucotricha) can severely reduce carrying capacity of pastures and cause damage to the skin, fleece and eyes of stock.
Description
- perennial grass to approximately 1m high
- leaves are mid-dark green, 5mm wide with a ligule 3mm long
- hairs on the leaf surface, and at the junction of the leaf blade and sheath
- flowers form a branched tuft (panicle) 400mm long.
Chilean Needle Grass
The illustration below compares Australian speargrass (Austrostipa spp. ) native grass (top illustration) to the Chilean needle grass (below illustration)
- leaves are 1-5mm wide and 30cm long
- flower heads droop, 40cm long
- seeds are 8-10mm long with a 1mm corona and a 60-90mm awn (bent twice).
Texas Needle Grass
- Leaves are 1-5mm wide and 30cm long
- Flower heads droop, 25cm long
- Seeds are 6-9mm long with a 1mm corona (with long hairs) and a 35-90mm awn (twisted and bent).
Why is it a problem?
- both grasses are highly unpalatable to stock
- can greatly reduce carrying capacity, and decrease pasture productivity by 50% in summer
- long sharp seeds can damage the fleece, skin and eyes of livestock
- heavy infestations can reduce biodiversity through competition with native grasses and other flora
- widespread infestations could also increase the price of meat and wool products.
Distribution
- Mount Lofty Ranges – isolated outbreaks
- near Jamestown and Lucindale
Ecology
- flowering period throughout South Australia is September to December
- in addition to normal seeds, Chilean needle grass has hidden, self-fertilising seeds in the flowering stems. It can therefore reproduce despite grazing, slashing or fire.
How it spreads
- seeds are carried by machinery, clothing, footwear or livestock
- harvesting of hay and the movement of water can also disperse seeds long distances from their source.