What Is “Apocynum sibiricum”? A Critical Comment on the Long-Term Taxonomic Homonymy

The necessity of the typification of the Apocynum L. s.l. (incl. Poacynum Baill. and Trachomitum Woodson) (Apocynaceae) species is crucial for future dogbane diversity estimations. Still, the original material of many taxa of the genus Apocynum s.l. is doubtful or remains to be discovered. This study’s topic is resolving a long-term taxonomic homonymy around the widely used binomial “A. sibiricum”. The misusing of the name “A. sibiricum” became a reason for long-term misunderstanding of the meaning of the binomial Poacynum sarmatiense (Woodson) Mavrodiev, Laktionov & Yu.E.Alexeev (A. sarmatiense (Woodson) Wissjul.; T. sarmatiense Woodson) and therefore for the misestimation of the Apocynum s.l. diversity in Russian and other Eurasian floras. Resolving this issue, here, we designate the lectotype of A. sibiricum Jacq. and the name “A. sibiricum Pall.” was validated within Poacynum as P. pallasianum Mavrodiev, Sytin, Laktionov & Vasjukov nom. nov. (Apocynum sibiricum auct., non Jacq.) with the lectotype selected from the original collections of Peter Simon Pallas.