The background of dormancy and optimal germination parameters were studied in four populations of masterwort (Peucedanum ostruthium, Apiaceae). The species is an alpine plant whose roots are used for flavouring and medicinal purposes. Peucedanum ostruthium is characterised by a (non-deep)-morphophysiological dormancy with an underdeveloped embryo. The optimal germination temperature is 26 degrees C and light is required for germination. Application of exogenous gibberellic acid (GA(3)) decreased germination percentage in optimal conditions but increased it under non-optimal conditions, with the exception of one population where germination failed completely when GA(3) was applied. This population was characterised by a lower mericarp and embryo size. The requirement for afterripening and high temperature for germination prevents germination of the mericarps when they are ripe in the autumn. Thus germination is delayed in alpine conditions until the following late spring/early summer, when late frosts cannot damage young plantlets.