Dryopteris affinis
Environmental Weed (2024)
Biostatus
Exotic
Category
Vascular
Structural class
Ferns
Detailed description
Deciduous, terrestrial ferns. Rhizomes stout, erect, often covered in dead stipe bases. Stipes 100–400 mm long, pale brown. Stipes and rachises densely covered in orange-brown scales. Laminae elliptic or narrowly elliptic, 2-pinnate, 0.3–1.25 × 0.15–0.3 m, glossy yellowish green to dark green. Primary pinnae in 25–50 (or more) pairs, narrowly triangular or ± oblong, tapering at apices, sessile, 80–150 × 20–30 mm, with a darkish patch near junction with rachis when fresh. Secondary pinnae in 15–30 pairs, oblong, adnate or decurrent on pinna midrib, obliquely truncate at apices, ± entire or sparingly toothed only at apices, to 15 × 7 mm; secondary pinnae on the basal pair of primary pinnae ± equal in length either side of midrib. Sori round, 1–5 pairs on each secondary pinna, often confined to upper pinnae, covered by reniform indusia which are rolled under sporangia when young.
Habitat
Widespread weedy fern of mostly easterly parts of New Zealand. Often in urban areas where it grows along streams or in wasteland. Also colonised plantation forestry, gullies and coastal forest.
Conservation status
Not applicable
Detailed taxonomy
Family
Dryopteridaceae
Ecology
Year naturalised
1980
Origin
Europe, Asia
Other information
Etymology
affinis: From the Latin ad + finis ‘to the boundary’, means ‘neighbouring’, ‘allied to’, ‘akin to’
Environmental Weed (2024)
This plant is named in a list of 386 environmental weeds in New Zealand 2024 prepared by DOC. 759 candidate species were considered for inclusion on this new comprehensive list of environmental weeds in New Zealand. The species considered were drawn from published lists of weed species, lists of plants that must be reported or managed by law if observed, existing national and regional programmes and agreements for pest management, and species already managed by the Department of Conservation (DOC). Candidate species were then assessed to see if they were fully naturalised and whether they have more than minor impacts in natural ecosystems. Read the full report here.
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.
DRYAFF
Referencing and citations
References and further reading
Brownsey PJ. 1988. In: Webb CJ, Sykes WR, Garnock-Jones PJ. Flora of New Zealand, Volume IV. Naturalised Pteridophytes, Gymnosperms, Dicotyledons. Botany Division, Department of Scientific and Industrial Research, Christchurch, NZ. 1365 p.
Attribution
Fact Sheet Prepared for NZPCN by: P.J. de Lange (10 November 2012). Description adapted from Brownsey in Webb et al. (1988).