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, and as the spinulose woodfern in North America.

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.

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.

References

Dryopteris carthusiana in Flora of North America

Further reading

carthusiana
Category:Ferns of the Americas
Category:Ferns of Asia
Category:Ferns of Europe
Category:Flora of Asia
Category:Flora of Europe
Category:Flora of North America
Category:Plants described in 1786