Alsophila cunninghamii
Common name
gully tree fern, slender tree fern, ponga
Synonyms
Cyathea cunninghamii Hook.f.
Family
Cyatheaceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Ferns
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.
CYACUN
Chromosome number
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
Brief description
Tall tree fern with green-stalked soft leaves to 3m long. Trunk to 20m tall, slender, old leaves fall off leaving just the base. Leaf stems covered in small red and white star-shaped hairs, star-tipped scales and pointed scales (lens needed). Sporangia arranged in small half capsules underneath leaves.
Distribution
Indigenous. New Zealand: North, South and Chatham Islands (mainly western from Te Paki (Unuwhao Bush) south to Wellington, and along the north-west and western side of the South Island). Also Australia (Queensland, New South Wales, Victoria and Tasmania).
Habitat
Coastal, lowland to montane in wet forests - especially along riversides, in gullies and in valley heads. An especially prominent species in karst country where it often fringes dolines and cave entrances.
Features
Trunks to 20 m tall, 50-150(-450) mm diameter, usually solitary, rarely bifurcated near apex, slender, bearing dark brown oval stipe scars and toward the apex dark brown, appressed stipe stubs. Stipes slender, adaxially golden-brown to yellow, abaxially black-brown, rugose, bearing scales, scales variable, up to 35 × 1-3 mm, with entire, fragile margins devoid of spines, apex terminated by 1 mm long apical seta; some scales hyaline, chartaceous, dull or glossy, dark golden-brown, others distinctly thicker, dark brown, lustrous. Fronds to 3 m long, held horizontally with distal portion slightly decurved with the apex distinctly upturned; 3-4-pinnate, soft, adaxially dark green to yellow-green, abaxially paler; dead fronds persistent only on immature plants, otherwise dehiscing to leave a short stipe base stub which soon decays leaving a small oval stipe scar. Longest primary pinnae 350-600 × 15-20(-30) mm wide, borne in the middle of the frond with pinnae either side gradually decreasing in length toward distal and proximal portions of stipe; lobes widely spaced; most basal 1-2 pairs free, others connected by narrow wing, largest lobes deeply lobulate; under surfaces bearing red and white stellate hairs and scales ending in single or stellate spines. Sori 1 per lobule; indusium cucullate, completely investing young sorus; paraphyses scarce, short, apical on receptacle; spores golden yellow to golden brown when fresh. Description adapted from Bostock (1998) and Brownsey & Smith-Dodsworth (2000) and based on measurements and notes made from fresh material.
Similar taxa
Closely related to Alsophila kermadecensis which is endemic to Raoul Island (Kermadec Island group) where A. cunninghamii is not present. In New Zealand proper Alsophila cunninghamii is most often confused with mamaku (Sphaeopteris medullaris) with which it often grows. Sphaeopteris medullaris differs by its stouter trunk covered in deep hexagonal stipe scars and by the stipe and lamina scales which bear numerous marginal spines which are consistently coloured dark, lustrous black, the fronds of S. medullaris tend to be arching with the apices decurved (never horizontal with a slightly decurved distal portion whose final apex is upturned), the indusia of mature S. medullaris sporangia is never cucullate and completely covers the sorus
Flowering
N.A.
Flower colours
No flowers
Fruiting
N.A.
Propagation technique
Easily cultivated provided it is planted in a deep, permanently moist (not waterlogged) soil, and in a semi-shaded site where it can grow up into the light. Plants respond well to regular applications of lime.
Etymology
cunninghamii: Named after Allan Cunningham (1791 – 1839) who was an English botanist and explorer, primarily known for his travels to Australia (New South Wales) and New Zealand to collect plants. Author of Florae Insularum Novae Zelandiae Precursor, 1837-40 (Introduction to the flora of New Zealand).
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (23 March 2011). Description adapted from Bostock (1998) and Brownsey & Smith-Dodsworth (2000) and based on measurements and notes made from fresh material.
References and further reading
Brownsey, P.J.; Smith-Dodsworth, J.C. 2000: New Zealand Ferns and Allied Plants. Auckland, David Bateman
Bostock, P.D.1998: Cyatheaceae. Flora of Australia 48: 193-205.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Alsophila cunninghamii Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/alsophila-cunninghamii/ (Date website was queried)