Australian sedge
Botanical Name
Carex longebrachiata
Family
Cyperaceae (sedge)
Also known as
Drooping sedge
Where is it originally from?
Australia
What does it look like?
Tall (<1 m), deep rooted, densely tufted sedge. Leaves (5 mm wide) are Y-shaped in cross section, with a dark brown sheath and harsh edges that can cut fingers when pulled. Flowering stems are triangular in cross section and sharply angled, and flowers hang at the end of long thin nodding stalks, grouped in catkin-like spikes (Oct-Feb). Seeds are small smooth triangular nuts held inside a long (5 mm) beaked covering.
Are there any similar species?
Distinctive flower and seedhead distinguishes it from other Carex species, which also prefer swampy areas.
Why is it weedy?
Produces large amounts of heavy seed that remains viable for 3-5 years and that falls close to the parent plant, creating a thick layer of germinating seedlings and maturing plants. Establishes and spreads rapidly on disturbed and exposed soil where pasture doesn’t thrive due to low soil fertility, drought, overgrazing or insect damage.
How does it spread?
Seed is heavy so it doesn’t spread far from the parent plant unless moved via contaminated soil or machinery. Also spreads vegetatively through pieces of root - breaking up the plant encourages seeds to germinate and the ground becomes reinfested.
What damage does it do?
Forms dense infestations and excludes native grasses in natural areas. Unpalatable to stock, and in pastoral areas with poor grass cover it grows thickly.
Which habitats is it likely to invade?
Dry areas of disturbed land: banks, clay soils, coastal areas, flat or hilly lowland, open pasture, sheltered and sloping scrubland, stone terraces.
What can I do to get rid of it?
1. Dig or grub out (small patches only): Best in summer.
2. Weed wipe (spring-summer): glyphosate (300ml/L).
3. Overall spray (spring-autumn): glyphosate (150ml/10L).
What can I do to stop it coming back?
Grazing does not control, only spreads seed, so exclude stock from infested pasture. Recheck area each year for new seedlings and regrowth and spray as needed. Dense plant cover in both pasture and natural areas will suppress germination of seeds still in the soil.
