The Portulaca oleracea complex in Belgium: an update

Since the publication, ten years ago, of a preliminary overview of the (micro-) species of the P. oleracea complex found in Belgium, knowledge about this group has increased. New research has shown that P. granulatostellulata and P. nitida (which were distinguished only by seed diameter and presumed ploidy level) are conspecific with P. papillatostellulata and P. oleracea s.str. respectively. Furthermore, in the previous overview some of the SEM images were mislabeled (e.g. the seeds of P. cypria and P. papillatostellulata were intermingled). Finally, a new, simple technique allows the assessment of the ornamentation of the seed coat, without the need for SEM photography. Because this could possibly lead to a better knowledge about this complex, a new identification key and new photos are presented.