Pteris macilenta
Common names
sweet fern
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Ferns
Detailed description
Terrestrial ferns. Rhizomes short, erect, scaly. Stipes 0.1–0.5 m long, yellow-brown, base scaly. Laminae 0.25–0.9 × 0.15–0.5 m, light green, 3-pinnate, ovate, thin; veins reticulated along midribs but free elsewhere. Pinnae widely spaced; most lower secondary pinnae stalked or sessile. Ultimate segments 5–15 × 3–5 mm, oblong, apices deeply toothed, margins almost smooth. Sori continuous along pinna margins on a marginal vein, protected by a membranous inrolled pinna margins.
Similar taxa
Pteris macilenta is most similar to P. saxatilis which is rather like a diminutive form of it. Pteris saxatilis differs from P. macilenta by the very widely spaced primary and secondary pinnae; laminae 0.15–0.5 × 0.12–0.25 m, and the ultimate segments up to 15 × 5 mm. Although Brownsey & Smith-Dodsworth (2000) state that intergrades exist between P. macilenta and both P. carsei (as P. comans) and P. saxatilis, this seems more likely to refer to hybrids between the latter two species as P. macilenta is genetically distinct from both P. comans and P. saxatilis and unable to hybridise with them (J.E. Braggins pers. comm.). Pteris carsei differs from both P. macilenta and P. saxatilis by the coriaceous (leathery) fronds, reticulate venation, overlapping pinnae and large ultimate segments. Pteris epaleata can be distinguished from P. macilenta as well as P. carsei and P. saxatilis by its dull adaxial frond surface.
Distribution
Endemic. New Zealand: North Island (widespread except for the central volcanic plateau and adjacent main axial ranges), South Island (common in the north, reaching a western southern limit near Greymouth and in the east on Banks Peninsula where it may have been planted (Wilson 2009)), Chatham Islands.
Habitat
Coastal to montane (in northern areas). Usually in dry, less heavily vegetated sites in forest but also on cliff faces and banks in light scrub. Especially common overlying calcareous or other base-rich rocks.
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
Pteris pendula Colenso
Taxonomic notes
The unpublished work of J.E. Braggins suggests that the name P. macilenta as applied by Allan (1961) and other authors is incorrect and that this name is actually the first legitimate name for the fern known as P. saxatilis. His work suggests that the correct name for the plant called here P. macilenta is in fact P. pendula Colenso. However, until such time as that research is published, and in line with other published works (e.g., Brownsey & Smith-Dodsworth 2000), the current usage of the names P. macilenta and P. saxatilis are retained.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Propagation technique
Easily grown from fresh spores and young plants transplant readily. Prefers semi-shade in garden settings, planted into a moist, rich free draining soil. Can be cold sensitive.
Other information
Etymology
pteris: A fern known to the ancient Greeks; from the Greek pteris
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.
PTEMAC
Chromosome number
2n = 116, 120
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
Referencing and citations
References and further reading
Allan HH. 1961. Flora of New Zealand, Volume I. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. Government Printer, Wellington, NZ. 1085 p.
Brownsey PJ, Smith-Dodsworth JC. 2000. New Zealand Ferns and Allied Plants. David Bateman, Auckland, NZ. 168 p.
Wilson H. 2009. Natural History of Banks Peninsula. Canterbury University Press, Christchurch, NZ. 144 p.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (17 January 2012). Description adapted from Brownsey & Smith-Dodsworth (2000).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Pteris macilenta Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/pteris-macilenta/ (Date website was queried)