974 Thlaspi arvense L.

This widespread species is an ancient weed. It is considered to originate from C. Asia. With its present distribution it belongs to the circumpolar plants (Hultén, Circumpol. Il, p. 248 and map 240). It has also been introduced into C. Africa, S. America (Chile) and New Zealand. Cf. also Meusel et al. 1965, map p. 179.