Alsophila colensoi
Common names
rough tree fern, mountain tree fern
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Ferns
Simplified description
Small tree fern with green-stalked roughish leaves to 1.5 m long. Trunk to 1 m 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.
Flower colours
No flowers
Detailed description
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)).
Similar taxa
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.
Distribution
Endemic. North Island ( from Mt Pirongia and the Kaimai Range south), South Island, Stewart Island/Rakiura.
Habitat
Montane to subalpine in dense forest, along stream courses, often near the bush line, sometimes extending into subalpine scrub.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Not Threatened
Detailed taxonomy
Family
Synonyms
Cyathea colensoi (Hook.f.) Domin
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
Not applicable—spore producing
Fruiting
Not applicable—spore producing
Propagation technique
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.
Other information
Cultivation
Occasionally available from specialist native plant nurseries.
Etymology
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.
NVS code
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.
CYACOL
Chromosome number
2n = 138
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | Regionally Not Threatened
Referencing and citations
References and further reading
Brownsey PJ, Smith-Dodsworth JC. 2000. New Zealand Ferns and Allied Plants. David Bateman, Auckland, NZ. 168 p.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange 22 March 2011. Description adapted from Brownsey & Smith-Dodsworth (2000).
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)