XVI International Botanical Congess

Anatomical and ultrastructural features in seed and seed coat structure of subfamily Spiraeoideae s. l. were studied. Being the most conservative they give significant, reliable information on systematics and phylogeny of this poorly studied subfamily. Archaic (Physocarpus, Gillenia), intermediate, geterobatmic (Spiraeanthus, Aruncus, Exochorda), advanced (Spiraea, Luetkea, Sibiraea, Chamaebatiaria) seed types were revealed. Genus Exochorda is regarded within separate tribe Exochordeae of Spiraeoideae subfamily. Genus Spiraeanthus appears to be part of Sorbarieae tribe.