The ovule primordium of Datisca cannabina is dizonate. The crassinucellate ovule has dermal, twolayered integuments that become crushed during their development, the exotesta excepted. The operculum contains the hilum and the micropyle and is lifted during germination without a special zone of rupture. The embryological and seed characteristics of Datiscaceae strongly support a close relationship with the Begoniaceae.