rough tree fern, mountain tree fern
Cyathea colensoi (Hook.f.) Domin
Vascular – Native
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
2n = 138
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Small tree fern with green-stalked roughish leaves to 1.5m long. Trunk to 1m tall or not present. Leaf stems covered in small red and white star-shaped hairs, star-tipped scales and pointed scales (lens needed). Sporangia arranged in small round hairy clusters underneath fronds.
Endemic. North, South and Stewart Islands from Mt Pirongia and the Kaimai Range south.
Montane to subalpine in dense forest, along stream courses, often near the bush line, sometimes extending into subalpine scrub.
Trunks prostrate, or erect (up to 1 m tall). Stipes slender, pale brown, finely rugose, bearing numerous scales. Scales pale brown to red-brown, lacking margin spines. Fronds up to 1.5 m long, held upright, 3-pinnate, soft; dead fronds falling (not persistent). Longest primary pinnae 150-400 mm long, adaxially hairy, abaxially covered in red stellate hairs and scales ending in single or stellate spines. Indusia absent; long hairs present amongst sporangia. Description adapted from Brownsey & Smith-Dodsworth (2000).
Most often confused with young Alsophila smithii with which it sometimes grows but distinguished by its prostrate to shortly erect trunk, finely and copiously hairy upper frond surface, absence of an indusia, and by the long hairs protruding from the sorus.
Difficult to grow and probably best left well alone. Some success has been had planting specimens into a rich, permanently damp soil within a shaded situation. Dislikes humidity and heat.
colensoi: Named after William Colenso (7 November 1811 - 10 February 1899) who was a Cornish Christian missionary to New Zealand, and also a printer, botanist, explorer and politician.
Where To Buy
Occasionally available from specialist native plant nurseries.
Fact sheet prepared for NZPCN by P.J. de Lange 22 March 2011. Description adapted from Brownsey & Smith-Dodsworth (2000).
References and further reading
Brownsey, P.J.; Smith-Dodsworth, J.C. 2000: New Zealand Ferns and Allied Plants. Auckland, David Bateman
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Alsophila colensoi Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/alsophila-colensoi/ (Date website was queried)