Classification
Class
Polypodiopsida
Subclass
Polypodiidae
Order
Polypodiales Link
Family
Dryopteridaceae Herter
Genus
Dryopteris Adans.
 Nomenclature
Scientific Name:
Dryopteris formosana (Christ) C.Chr., Index Filic. 266 (1905)
Synonymy:
  • ≡ Aspidium formosanum Christ, Bull. Herb. Boissier sér. 2, 4: 615 (1904)
Holotype: Hakuto, Taiwan, U. Faurie 687, 4 May 1903, P 00630715 (!online)
Etymology:
formosanus (Latin) – from Formosa (Taiwan)
 Recognition

Dryopteris formosana has an erect rhizome, dark brown to almost black scales on the stipe and rachis, laminae that are pentagonal and 3-pinnate to 3-pinnate-pinnatifid, 1–2 basiscopic secondary pinnae on the basal primary pinnae that are longer than the corresponding acroscopic secondary pinnae, aristate teeth on the ultimate lamina segments, light brown weakly inflated scales on the abaxial costa surfaces, and reniform indusia (Hoshizaki & Moran 2001).

 Distribution

North Island: Northland.

Altitudinal range: c. 15 m.

Collected as a self-sown plant in cultivation in Kerikeri.

Occurs naturally in China, Korea, Japan, Taiwan and Philippines.

Dryopteris formosana distribution map based on databased records at AK, CHR & WELT. Image: K.Boardman © Landcare Research 2020 CC BY 4.0
Dryopteris formosana distribution map based on databased records at AK, CHR & WELT. Image: K.Boardman © Landcare Research 2020 CC BY 4.0
 Habitat

Recorded as self-sown c. 5 m away from a cultivated plant.

 Biostatus
Exotic
 First Record

Ogle et al. (2021). Voucher AK 374687, 2018.

 Images
Dryopteris formosana. Herbarium specimen of a fertile frond showing elongated basal basiscopic secondary pinnae on the basal primary pinnae, AK 374687/A. Image: Auckland Museum © Auckland Museum All rights reserved
Dryopteris formosana. Herbarium specimen of a fertile frond showing elongated basal basiscopic secondary pinnae on the basal primary pinnae, AK 374687/A. Image: Auckland Museum © Auckland Museum All rights reserved
 Bibliography
Brownsey, P.J.; Perrie, L.R. 2021: Dryopteridaceae. In: Breitwieser, I. (ed.) Flora of New Zealand — Ferns and Lycophytes. Fascicle 31. Manaaki Whenua Press, Lincoln.
Christ, H. 1904: Filices Faurieanae. V. Filices Formosanae. Bulletin de l'Herbier Boissier, série 2, 4: 609–618.
Christensen, C. 1905–1906: Index Filicum. Hagerup, Copenhagen.
Hoshizaki, B.J.; Moran, R.C. 2001: Fern Grower’s Manual. Timber Press, Portland, Oregon.
Ogle, C.C.; de Lange, P.J.; Cameron, E.K.; Parris, B.S.; Champion, P.D. 2021: Checklist of dicotyledons, gymnosperms and pteridophytes naturalised or casual in New Zealand: additional records 2007–2019. Perspectives in Biosecurity Research Series 5: 45–116.