Polystichum wawranum
Synonyms
Aspidium wawranum Szyszyl. in Wawra
Family
Dryopteridaceae
Flora category
Vascular – Native
Endemic taxon
Yes
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.
POLWAW
Chromosome number
2n = c.164
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
Distribution
Endemic. New Zealand, Northern North Island and Chatham Islands
Habitat
Coastal to montane. Often on cliff faces, especially those composed of base-rich substrates such as calcareous sandstone, limestone, basalt and schist. A rupestral or terrestrial fern of coastal shrublands and forest, gorges, riparian forest as well as open sites on hillsides, in rough pasture or on alluvial terraces. It has also colonise urban areas where it sometimes a feature of roadside banks and cuttings.
Features
Rhizomes short, erect. Stipes 150–550 mm long. Stipes and rachises densely scaly. Scales filiform (hair-like); almost always widest at base; those from the stipe-rachis junction 40–120 microns wide at mid length; usually dark brown, but often appearing black to the naked eye; apex long and tapering; margins often with protrusions, which are usually blunt; often densely fimbriate around base, so much so that in young fronds the stipe and rachis scales appear to be underlain by a dense white tomentum. Lamina 270–590 × 110–280 mm; bipinnate with the basal primary pinnae of some large fronds becoming tripinnate; varying in colour from olive-green to blue-green, usually with primary and secondary costae blackish blue. Primary pinnae in 18–35 pairs, the longest 55–140 × 13–35 mm. Secondary pinnae usually adnate, but becoming free and sessile to almost stalked towards the base of primary pinnae, particularly in basal primary pinnae; often with only sparse marginal toothing, sometimes almost entire but for apical point. Sori round. Indusia peltate, ± flat, ± round, with entire, although often undulate and/or scalloped, margins; often deciduous; central dark area usually insignificant (c. < 10% of surface area).
Similar taxa
Polystichum wawranum is recognised by its hair-like scales, closely inserted and relatively long narrow pinnae, indusia mostly lacking obvious dark centres, and relatively small spores. It is likely to be confused only with P. neozelandicum subsp. neozelandicum and subsp. zerophyllum, which are distinguished from P. wawranum by having wider scales, indusia with larger dark centres, and larger spores. Polystichum wawranum is commonly sympatric with P. neozelandicum subsp. neozelandicum in northern New Zealand, otherwise its range overlaps with both P. neozelandicum subspecies only on the Chatham Islands.
Flowering
Not Applicable - Spore Producing
Flower colours
No flowers
Fruiting
Not Applicable - Spore Producing
Propagation technique
Easily grown from fresh spores and transplants. However, often slow to establish. Does best in a shaded site planted within a deep, free draining humus-enriched fertile soil. Polystichum wawranum benefits from regular applications of lime.
Threats
Not Threatened - though very scarce on the Chatham Islands
Etymology
polystichum: Many rows (of sori); from the Greek polus and stikhos; parallel rows of spore cases
Where To Buy
Occasionally sold by specialist native plant nurseries, usually as P. richardii
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (12 November 2012). Description adapted from Perrie et al. (2003)
References and further reading
Perrie, L.R.; Brownsey, P.J.; Lockhart, P.J.; Large, M.F. 2003A: Evidence for an allopolyploid complex in New Zealand Polystichum (Dryopteridaceae). New Zealand Journal of Botany 41: 189-215
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Polystichum wawranum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/polystichum-wawranum/ (Date website was queried)