Seed morphology, germination phenology, and capacity to form a seed bank in six herbaceous layer Apiaceae species of the Eastern Deciduous Forest

We compared seed mass, seed morphology, and long-term germination phenology of three monocarpic (M) and three polycarpic (P) Apiaceae species of the herbaceous layer of the Eastern Deciduous Forest. Seeds (mericarps) of the six species differed considerably in mass, shape, and ornamentation. Mean seed masses were ranked Cryptotaenia canadensis (M) < Thaspium barbinode (P) < Sanicula canadensis (M) < S. gregaria (P) < Osmorhiza claytonii (P) < S. trifoliata (M). Germination peaks occurred in the first or second spring following sowing. Germination of a few seeds was delayed until the sixth year. Regardless of seed mass or morphology, each species has the potential to form a (modified) Type III or (modified) Type IV persistent soil seed bank. Occurrence of a germination peak in the first or in the second year following seed maturity was related to time of dispersal in autumn and to type of seed dormancy.