Disentangling a polyploid complex within Crocus series Verni

In plants the occurrence of polyploid lineages, i.e. plants with multiple instead of two sets of chromo-somes, is quite common. Polyploids can originate as autopolyploids within a species, or by combining the genomes of different species resulting in allopolyploids. Within the group of spring crocuses a pol-yploid complex exists where it is unclear how it evolved and which species eventually contributed to polyploid formation. Among crocus species chromosome numbers vary in a wide range and do not clearly correlate with di- or polyploidy. To reconstruct the evolution of these polyploids we exemplarily combine chromosome counts, genome size estimations, phylogenetic analyses based on maternal- and biparental-inherited genomes, and morphometric data for all species potentially involved in the poly-ploids. Through this 'total evidence' approach we can show that polyploids in the Crocus heuffelianus group originated multiple times involving different parental genotypes and also reciprocal crosses. Partly chromosome numbers changed after polyploidization so that the numbers found in polyploids are no longer additive values of their parents. We conclude that in crocuses only an approach using ev-idence from diverse data can uncover the evolutionary history of species if polyploidization is involved.