Discovery of the Northern Hemisphere hybrid Potamogeton xsalicifolius in the Pilbara region of Western Australia
Abstract
The interspecific hybrid Potamogeton xsalicifolius (= P. lucens x P. perfoliatus), so far known only from several countries of Europe and a few countries of Asia, was discovered in Western Australia. Morphology of the Australian specimens fits the range of variation observed in Eurasian specimens.
DNA sequencing confirmed the morphological identification as a hybrid P. lucens x P. perfoliatus, and identified P. lucens as the maternal parent. This identity is surprising because neither of the parental species are known to occur in Western Australia and P. lucens currently does not even occur in the continent.
Three possible explanations for the occurrence of P. xsalicifolius in Western Australia are discussed: its relictual occurrence from a time when both the parental species occurred there, long-distance dispersal of a hybrid seed from Eurasia and the remnant of local cultivation or intentional planting.