This paper presents the results of micromorphological studies of Portulaca oleracea aggregate seeds deposited at the Herbarium of the Department of Systematic and Environmental Botany (POZ), Adam Mickiewicz University in Poznań, Poland, based on scanning electron microscopy. The seed surface ultrastructure was studied and the following seven morphotypes (species) were noted: P. daninii, P. granulatostellulata, P. macrantha, P. nitida, P. oleracea s. str., P. papillatostellulata, and P. trituberculata. New alien taxa for the flora of Poland, P. daninii, P. macrantha, and P. papillatostellulata, were recorded. The original photos of the seed surface ultrastructure of the studied morphotypes are included.