Threat: High threat environmental weed.
Description: Robust, open tufted, summer-growing perennial grass. Grows to One metre, with creeping underground stems. It becomes dominant in damp, disturbed areas and its dense growth smothers all competing ground flora and prevents the establishment of over-storey plants. Widely used in irrigated pasture.
Flowers and seeds: Four to seven long drooping spikes each 4–7cm long that are purple-green with tufted hairs at the base. Seeds are flattened and in rows along the flowering spike. Darkened and sticky when ripe. Flowers from December to July.
Leaves and stems: Leaves are 15–45cm long, wide and flattish with a prominent midrib, mid to dark green with the upper surface often tinged reddish-purple. Sparsely hairy around where the leaf meets the stem. Stem is smooth, erect, but arching and often tinged purple.
Note: Mature seed readily adheres to most surfaces and is regularly transported on animals, machinery and clothing.
Control measures: Hand weeding, spot spraying.
Dispersal: Animal, machinery, water, vegetative, wind.