Nassella neesiana, Chilean Needle Grass

Image/s
Category
Grasses and Sedges
Scientific Name
Nassella neesiana
Common Name/s
Chilean Needle Grass
Weed Information

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

Threat: High threat environmental and agricultural weed.

Description: A tufted, perennial, tussock grass growing to about 1 metre tall with a nodding, loose flower head which contains spear-like flowers with long twisting awns. Active summer growing species adaptable to a wide range of conditions.

Flowers and seeds: Flowering seed heads are a distinctly purplish colour and have a nodding habit. Seeds 8–10mm long with a very sharp point and a 60–90mm long twisted awn bent at two points. The seed has a very distinctive raised membranous crown or collar where the awn attaches to the seed. It also produces stem and basal seeds within and at the base of some stems. Flowers October to February.

Leaves and stems: Forms an erect, robust tussock. It has narrow, hairless or sparsely hairy leaves up to 30cm long and 5mm wide, which are normally flat but sometimes rolled and feel rough to the touch. Leaves are mid to dark green but can become yellow or straw-like in cold conditions.

Note: Seeds frequently spread by animals and machinery (mostly slashers). Aggressively invades grassy ecosystems and agricultural land causing injury to stock. Very difficult to control when established, so small or scattered outbreaks urgently. It can produce more than 20,000 seeds per square metre.

Similar indigenous species: Often confused with a number of native spear grasses (Austrostipa spp.), grasses can be easily distinguished from needle grasses by a collar on the seed.

Control measures: Hand weeding, spot spraying, slashing, mowing and re-vegetation.

Dispersal: Animal, machinery, water, wind, seeds.