61 Polystichum aculeatum (L.) Roth

Syn.: P. lobatum (Huds.) Chev.

This widespread species seems difficult to circumscribe. It is here taken in a very wide sense, including on this map much of P. setiferum (no. 62). S of the broken line through the Mediterranean probably only P. setiferum occurs. Both species seem to overlap in a large part of W. C. and S. Europe. The species s. lat. occurs also outside the map area (see the notes in the margin of the map). It is recorded among the circumpolar plants (Hultén, Circumpol. I, p. 150 and map 141). In this respect other closely related taxa, for instance P. californicum (D. C. Eat.) Underw., P. dudleyi Maxon and P. mohrioides (Bory) Presl var. scopulinum (D. C. Eat.) Fem. in N. America, are taken into consideration.