Dryopteris carthusiana (Villars) H.P. Fuchs
spinulose wood fern
Family: Dryopteridaceae

scales on stipe
basal pinnae

Fronds of Dryopteris carthusiana range from 15-75 cm in length, and most healthy plants in our area are at least 40 cm long. The blades are clearly longer than wide, 2 pinnate-pinnatifid or further divided. Tan scales are conspicuous at least at the base of the stipe.

Dryopteris carthusiana and D. intermedia are similar in general appearance and both are common. For D. carthusiana the lower basal pinnule of the lowest pinna is longer than the adjacent pinnules, and it is shorter than the adjacent pinnules in D. intermedia. Some fronds are difficult to place on this basis and it is wise to look at a large sample of leaves if there is any question. Fronds of D. intermedia are evergreen and those of D. carthusiana are not, a character that is very helpful in winter and spring. Glands on the indusia and midribs of blade segments of D. intermedia are a good character, but they can be difficult to see, tend to wear off as the fronds age and generally require a good hand lens or dissecting scope for observation. There are no glands on D. carthusiana.

D. expansa, a very rare species in Wisconsin, is similar to D. carthusiana, but the lower basal pinnules of the lowest pinnae of D. expansa are very large relative to the upper basal pinnules. See the key to Dryopteris species or the Flora of North America for more information.

D. carthusiana ranges across Canada and throughout the northeastern U.S., south to South Carolina and Arkansas and west to Nebraska and North Dakota. It is also known in the northwest from Montana to Washington. It is found throughout Wisconsin. Habitats include moist forests and swamps.

Key to Ferns

Introduction to Ferns

Glossary of terms

List of all Pteridophytes

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