Calendula L. (Asteraceae) specimens held at AVE (Herbarium of the University of Aveiro)

Recently, P. Silveira et al. published partial taxonomic revisions of the genus Calendula , covering the Iberian Peninsula, Morocco, the Canary Islands and some taxa from Algeria and Tunisia. In these studies, achene morphology and genome size estimates were considered particularly relevant for taxonomic purposes, alongside chromosome number, leaf and flower/capitula morphology and life span. The taxonomic concept previously proposed by C. Heyn et al. for the annual plants with 44 chromosomes was adopted, but a mixed approach was preferred for the perennial plants with 32 chromosomes: most of the subspecies recognised by H. Ohle were adopted, but all were placed under C. suffruticosa rather than split between this taxon and C. incana . This approach was preferred because a gradient of morphological variation and DNA content was observed amongst the plants that H. Ohle had included in the two species, rather than a clear and consistent separation between the two groups. Furthermore, O. Plume, who studied the genus using molecular markers, found no evidence of closer phylogenetic relationships amongst the taxa within these two species. Overall, these recent taxonomic revisions expanded and consolidated knowledge of the genus' taxonomy and diversity. The dataset includes Calendula specimens held at AVE (Herbarium of the University of Aveiro). It comprises 406 occurrence records (specimen metadata), together with images of 77 specimens, which were used in the recent taxonomic revisions by P. Silveira et al., eight of which being type specimens. Data for most of these specimens had already been published in those papers, but in a more abbreviated form, lacking the completeness of the Darwin Core format adopted here, which facilitates use by other researchers. Most of the specimens were collected by P. Silveira and his team, but numerous donated specimens are disclosed here for the first time, such as those received from BH herbarium that were collected by O. Plume in regions not sampled by P. Silveira, like Sicily (Italy) and Lebanon, which were also used during her PhD research. In addition, the dataset contains many duplicates from the HAL herbarium, collected by H. Ecklerlein, H. Meusel, H. Ohle and K.H. Rechinger and used by H. Ohle in his taxonomic revisions of the perennial Calendula taxa and which have not been cited in our previous publications.