Phragmites is a perennial grass that grows up to 3 m tall on water margins. It has bamboo-like stems which carry long, wide, flat leaves that taper to a point. It has large, fluffy, purplish-brown flower heads, and seed grain which is covered in silky hairs. It is similar to giant reed (Arundo donax), but phragmites is smaller and the stems are narrower in proportion to the leaves.
Phragmites reproduces asexually by rhizomes and, in its native range, forms dense patches on the edges of waterways. It is expected to invade waterways in New Zealand if it becomes more widespread, however it is unlikely to spread much unless distributed by people spreading rhizome fragments.
What to do
Contact MAF Biosecurity New Zealand on 0800 80 99 66 if you find this plant.
Please also see the phragmites fact sheet (883 KB).
Page last updated: 19 August 2009