Recurrent hybridisation events between Primula vulgaris, P. veris and P. elatior (Primulaceae, Ericales) challenge the species boundaries: Using molecular markers to re‐evaluate morphological identifications

Three Primula species, Primula vulgaris, P. veris and P. elatior, have been objects of fascination for gardeners and botanists over several centuries. The species are able to hybridise, and where they co-occur, hybrids are commonly found. In Denmark, Møns Klint on the island of Møn and Købelev Skov on Lolland are examples of localities where all three species occur and where the hybrids P. ×digenea, the hybrid between P. vulgaris and P. elatior, and P. ×polyantha, the hybrid between P. veris and P. vulgaris, can also be found. To investigate relations between the species and their hybrids, 168 specimens from 10 geographical locations were sampled for genetic analysis using DNA markers and identified based on morphological traits, primarily inflorescense structure, the size, shape, colour and markings of corolla and leaf basis, leaf blade texture and hairiness. After identifying species-specific SNPs in the internal transcribed spacer sequence, these were used to resolve species and hybr...