Species

Cyathea medullaris

Etymology

Cyathea: From the Greek kyatheion 'little cup', referring to the shape of the indusium
medullaris: pithy (trunk)

Common Name(s)

Black tree fern, Mamaku, Black mamaku

Threat Status

Non Threatened

Status 2004

Non Threatened

Authority

Cyathea medullaris (G. Forst.) Sw.

Family

Cyatheaceae

Flora Category

Vascular - Native

Synonyms

Sphaeropteris medullaris (G.Forst.) Bernh.; Cyathea medullaris var. polyneuron (Colenso) C.Chr.; Cyathea medullaris var. integra Hook.; Cyathea polyneuron Colenso; Polypodium medullare G.Forst.;

Distribution

Indigenous. Occurring form the Three Kings Islands south to Stewart and the main Chatham Islands. Uncommon in the drier eastern portion of the South Island, and apparently absent from Canterbury and Otago.

Habitat

Common in lowland forest throughout the North Island. Primarily in wetter coastal areas of the South Island.

Features

Tree fern up to 20 m tall. Trunk black covered with hexagonal stipe bases. Stipes thick, black, harsh to touch, covered in black scales. Scales with marginal spines. Fronds up to 5 m long, arching upwards from crown, 3-pinnate, leathery, dead fronds falling (except in very young plants). Longest primary pinnae 0.4-1 m long, undersurfaces bearing scales with marginal spines. Indusia completely covering sori at maturity, splitting irregularly.

Similar Taxa

Easily recognised by trunk with its distinctive hexagonal stipe scars and by the scales which possess marginal spines.

Flowering

None (spore bearing)

Main Flower Colour

No Flowers

Fruiting

None (spore bearing)

Propagation Technique

Can be grown from fresh spores (but slow). Young plants transplant easily and freshly felled trunks will usually resprout if planted and carefully watered. Easy, once established in a variety of conditions. Should not be removed from the wild unless with landowner permission.

Threats

Not Threatened.

Chromosome No.

2n = 138

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

Where To Buy

Commonly cultivated. Not as freely available from nurseries as other tree ferns because it is slow from spores and sporelings are notorious for failing following transplants.

References and further reading

Esler, W.R. 1976. Succession of fronds of mamaku (cyathea medullaris). Wellington Botanical Society Bulletin, 39: 41-43

This page last updated on 3 Feb 2013