Phragmites
Botanical Name
Phragmites australis
Family
Poaceae (grass)
Also known as
Common reed
Where is it originally from?
Temperate zones in both hemispheres
What does it look like?
Emergent aquatic and marginal perennial grass (<3 m tall) with bamboo-like stems and flat, long, wide (60 cm x 3 cm) bluish-green leaves that taper to a point. Large, fluffy, purplish-brown flowerheads (40 cm long) produce seed grain covered in silky hairs.
Are there any similar species?
Phragmites karka bamboo and Giant reed (Arundo donax).
Phragmites karka has longer glumes and rhachilla hairs than Phragmites australis.
Giant reed has leaves arranged in two rows while Phragmites does not.
Why is it weedy?
Aggressive growth and spread by seed and rhizomes allows it to take over large areas of damp group alongside waterways and in wetlands.
How does it spread?
Seeds and rhizome fragments are spread by water, and also by deliberate planting. Flowering and seed production are highly variable in NZ.
What damage does it do?
Forms dense stands and crowds out native species.
Which habitats is it likely to invade?
Waterways and wetlands.
What can I do to get rid of it?
If you suspect that you have found phragmites, do not touch it. This pest plant is under an active national eradication programme, and any attempt to get rid of it could accidentally spread the pest. Any plants found that are suspected to be this species should be reported to Biosecurity New Zealand using the pests-and-diseases hotline on 0800 80 99 66. They will work with you to control the weed.
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