69 Dryopteris expansa (Presl) Fras.-Jenk. & Jermy

Syn.: D. assimilis S. Walker

This widespread species was cytologically distinguished under the name D. assimilis in 1961 by. S. Walker (Amer. J. Bot. 48, p. 607-614). Up to that time it was hidden in D. dilatata (Hoffm.) A. Gray and thus included in the map of D. dilatata by Hultén in Amphi-atl. 1958 (no. 156). Cf. also Meusel et al. 1965, map p. 18. The occurence of D. expansa in Siberia is insufficiently shown on the present map. For the occurrence of D. dilatata and expansa (D. assimilis) in Europe see Atlas Fl. Eur. 1/1972, maps 130 and 132 (incomplete as to E. Europe). A comprehensive treatment of these species in Sweden is given by Nannfeldt in Bot. Not. (Lund) 119/1966, p. 136-152, and for Poland by H. Piekos-Mirkowa in Soc. Bot. Polon., Monogr. Bot. 59/1979.