Pelophylax Lessonae
The genus Pelophylax was created in 1843 by the Austrian zoologist Leopold Fitzinger to gather the green frogs of Europe that he wanted to distinguish from the brown frogs of the genus Rana created by Linné.
Most authors of the nineteenth and twentieth centuries did not follow Fitzinger: they classified green frogs with brown frogs in the genus Rana.
In the early 20th century, the term "green frog" was used to refer to the only species recognized by Linnaeus in 1758, namely Rana esculenta, the edible frog.
This frog with its "varieties" was considered to be widespread throughout Europe.
A large green frog, the Laughing Frog (Rana ridibunda), and a small frog, the Lessona Frog (Rana lessonae), were later recognized as valid species.
It was not until the second half of the 20th century that the work of a Polish researcher, Leszek Berger (1966, 1973), began to clarify the understanding of the great variety of European green frogs.
