''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 North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. 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''. Dryopteris carthusiana6

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. It is known to be able to use artificial light to grow in places which are otherwise devoid of natural light, such as

Niagara Cave Niagara Cave is a limestone cave located in Harmony, Minnesota. The cave is approximately 200 feet (61 m) deep; features include an underground stream, 60-foot waterfall, fossils, stalactites and stalagmites. The cave is privately owned, with ...

References

Dryopteris carthusiana
in ''

Flora of North America The ''Flora of North America North of Mexico'' (usually referred to as ''FNA'') is a multivolume work describing the native plants and naturalized plants of North America, including the United States, Canada, St. Pierre and Miquelon, and Greenla ...

References

Further reading