916 Erysimum cheiranthoides L.

Within this widespread species two subspecies are distinguished (Ahti in Arch. Soc. Zool. Bot. Fenn. Vanamo 16:1/1961, p 22 ff.; F l. Eur. 1/1964, p. 274f.). It seems reasonable to assume that subsp. cheiranthoides originates from E. Europe and/or W. Asia from where it has spread as a field weed westwards over most of Europe and to N. America. Subsp. altum Ahti is probably native in NE. Europe, Siberia and northwestern N. America. It is also favoured by agriculture. E. cheiranthoides s. lat. nowadays has a circumpolar distribution pattern (Hultén, Circumpol. Il, p. 304 and map 296). Cf. also Meusel et al. 1965, map p. 191.