Dryopteris carthusiana

Dryopteris carthusiana is a species of fern native to damp forests throughout the Holarctic Kingdom. It is known as the narrow buckler-fern in the United Kingdom,[1] and as the spinulose woodfern in North America.[2]

Dryopteris carthusiana
Growing in Pennsylvania
Conservation status
Secure  (NatureServe)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Class:	Polypodiopsida
Order:	Polypodiales
Suborder:	Polypodiineae
Family:	Dryopteridaceae
Genus:	Dryopteris
Species:	D. carthusiana
Binomial name
Dryopteris carthusiana (Vill.) H.P. Fuchs
Synonyms
D. spinulosa (O.F. Muell.) O. Kuntze D. austriaca var. spinulosa (O.F. Müll.) Fiori Polypodium carthusianum Vill. Polypodium spinulosum O.F. Müll.

It is a tetraploid of hybrid origin, one parent being Dryopteris intermedia, known in North America as the intermediate wood fern, and an unknown, apparently extinct species dubbed Dryopteris semicristata, which is also the presumed parent of the hybrid-origin Dryopteris cristata.

Showing sori and leaflet shape

This fern is often confused with several other wood fern species, including D. intermedia, D. campyloptera, and D. expansa. It especially extensively shares the range of D. intermedia, but the two may be distinguished by the innermost pinnule on the bottom side of the bottom pinna: this pinnule is longer than the adjacent pinnules in D. carthusiana, but shorter or even in D. intermedia. D. carthusiana is a sub-evergreen species, its fronds surviving mild winters but dying back in harsh winters.

A nature print of Dryopteris carthusiana