Great reedmace

Great reedmace is a perennial, marginal aquatic reed that can grow up to three metres tall.

Description

• Leaves are wide, flat, stiff, and pale grey/green, turning golden in autumn.

• Flowers are erect, sausage-shaped, and has dark brown/black inflorescences.

• Male flowers disintegrate after shedding the pollen, leaving the stem tip naked.

• Seeds are nutlike with long, slender hairs.

• Rhizomes form a thick mat.

• Seeds are dispersed by wind, water, and animals, or vegetatively via rhizomes.

• Habitats include wetlands, and water bodies and margins up to one metre deep

What you need to know

Great reedmace forms dense thickets, suppressing native vegetation and altering flow regimes. It has the potential to directly compete or hybridise with threatened taonga species like raupō.

Management approach

Great reedmace is declared an unwanted organism by the Ministry for Primary Industries (MPI) because it is capable of causing harm to the natural environment, physical resources or human health in Aotearoa/New Zealand.

These species pose a high risk to our environment, economy, recreation, and cultural values.

Rules

Any species declared a pest, including unwanted organisms, cannot be sold or be in a place where plants are being sold. Pest plants cannot be propagated, bred, or multiplied, communicated, released, or cause to be released, or otherwise spread.

Control

Do not attempt to undertake control of great reedmace yourself. Report any sightings to us.