Māori name: Mamaku

English name: Black tree fern

Scientific name: Cyathea medullaris

NZ Status: Native

Conservation Status (NZTCS): Not Threatened

Found: Common in damp, lowland forests throughout much New Zealand.  Absent or uncommon in drier regions of the South Island, including the east coast and Otago.

Did you know? Mamaku is the tallest and fastest growing New Zealand native tree fern.

Photo Credit: Allison Buchan

A symbol of new life, mamaku plays a role in the hatching of chicks and the health of mothers. 

Hihi, one of Aotearoa’s rarest birds, furnish their nests and blanket their eggs with mamaku fibres, collected from the kōrau (the spiral-shape fern new frond). From the trunk of the fern, hihi collect matted aerial roots to form the foundations of their nests. 

In rongoā/ Māori medicine, the mamaku is important after childbirth. The bruised pith can be used as a poultice to relieve inflamed breasts. A tonic produced from boiling fronds aids in the discharge of the whenua/placenta.

Mamaku trunks also support new life amongst other plants, acting as a perch for seedlings of several plant species, including kawakawa and rangiora. Its fallen fronds provide rich soil for larger trees to establish.

One of the tallest tree ferns in the world, mamaku can soar 20 metres above the ground, their hexagonal scars showing where earlier leaves have fallen away. 

Look for them: Mamaku prefer lowland areas and damp soils, so they are more common in the lower reaches of the valley, along the Te Māhanga, Beech and Swamp tracks.  You may also be able to pick out the fronded-tops of taller specimens by looking down into the valley from the suspension bridge or upper dam.