The New Zealand Plant Conservation Network

Species

Cyathea kermadecensis

Etymology

Cyathea: From the Greek kyatheion 'little cup', referring to the shape of the indusium
kermadecensis: From the Kermadec Islands

Common Name(s)

Kermadec tree fern

Current Conservation Status

2012 - At Risk - Naturally Uncommon

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - At Risk - Naturally Uncommon
2004 - Range Restricted

Qualifiers

2012 - IE, OL
2009 - RC, IE, SO

Authority

Cyathea kermadecensis W.R.B. Oliv.

Family

Cyatheaceae

Brief Description

Tall tree fern with green-stalked soft leaves to 4m long inhabiting Raoul Island in the Kermadec Islands. Trunk to 20m tall, slender, old leaves fall off whole. Leaf stems covered in small star-tipped scales and pointed scales (lens needed). Sporangia arranged in small half capsules underneath fronds.

Flora Category

Vascular - Native

NVS Species Code

CYAKER

Structural Class

Ferns

Synonyms

Alsophila kermadecensis (W.R.B.Oliv.) R.M.Tryon

Distribution

Endemic. Kermadec Island group, Raoul Island only

Habitat

Confined to the higher parts of Raoul Island where it is a locally conspicuous component of ravine, gully, gorge and cliff forest in the wetter part of the island.

Features

Gracile tree fern up to 20 m tall. Trunk slender, often curved, covered with diamond-shaped stipe scars. Stipes slender, copiously invested in woolly hairs and pale brown to brown scales lacking marginal spines. Fronds arching from crown, up to 4 x 2 m, 3-pinnate; dead fronds falling. Primary pinnae up to 400 mm long, dark green to yellow-green above, subcoriaceous to membranous, undersides paler, bearing numerous scales; scale apices terminated by single or stellate spines. Indusia cucullate.

Similar Taxa

On Raoul Island this species is sympatric with C. milnei Hook.f., from which it is easily distinguished by its taller, more slender trunk which lacks a persistent skirt of dead frond and bears numerous rhomboid stipe scars; by the soft rather than coriaceous, raching rather than horizontal fronds, and hood-shaped rather than cup-shaped indusia. The scales on the underside of the pinnae in C. kermadecensis are not curled and are terminated by a single or stellate spine. Cyathea kermadecensis is very closely related to C. cunninghamii Hook.f., which is common in New Zealand proper and Australia. From that species C. kermadecensis is best distinguished by its clean trunks which lack persistent stipe bases, less divided fronds and by the absence of stellate hairs on the frond undersides.

Flowering

Not applicable - spore producing

Flower Colours

No Flowers

Fruiting

Not applicable - spore producing

Propagation Technique

Easily grown from spores. Young plants are very cold sensitive and will not tolerant any frost, wind or drought. They are best planted in a warm, sheltered, permanently damp site. Once established this species is very fast growing.

Threats

Not Threatened. Listed because it is a narrow range naturally confined to Raoul Island. In the past it had been regarded as highly threatened but in recent years numerous plants of all different age classes have been found.

Chromosome No.

2n = 138

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 30 Dec 2014