Cynanchum rossicum, Kleopow, 1929

Mosyakin, Sergei L., Davydov, Denis A. & Shiyan, Natalia M., 2017, The authorship and nomenclature of Vincetoxicum rossicum (Cynanchum rossicum) and V. meoticum (C. meoticum) (Apocynaceae: Asclepiadoideae), with considerations on nomenclatural uncertainties in determining the validity of names, Phytotaxa 307 (1), pp. 75-83 : 78

Validation of Cynanchum rossicum in 1941?

Our screening of botanical literature in which C. rossicum might have been accepted after 1929 demonstrated that the species was mentioned in at least two publications prior to validation of V. rossicum by Barbaricz (1950). One is a rather well-known article by Kleopow (1941) on the development of the plant cover of broadleaved forests in Eastern Europe, which was partly based on the mentioned dissertation finalized in 1941 and published much later (Kleopow 1990). Another is the treatment of Cynanchum by B.A. Fedtschenko (1941; modern transliteration: Fedchenko) in the 7 th updated and expanded edition of the popular manual for identification of vascular plants of Middle Russia initially prepared by Majevski (modern transliteration: Mayevskiy). Judging from the internal data available, both publications were released almost simultaneously: the book with Kleopow’s article was approved for publication (“Подписано к печати”) on 12 May 1941, while the approval statement for the 7 th edition of Majevski’s manual is dated by 19 May 1941, just one week later. Of course, the actual publication dates may differ from those approval dates; however, according to Art. 31.1 of ICN ( McNeill et al. 2012), in the absence of proof establishing some other date, the one appearing in the printed matter must be accepted as correct.

In the article (Kleopow 1941) the name C. rossicum is mentioned just once, at the bottom of page 215 in the following context: Kleopow lists some species occurring in oak forests of the elevated parts of the Volga area and mentions (in the reversed order, quite normal for Russian phrases): “... and, closely related to Cynanchum scandens , the endemic species C. rossicum ” (in Russian: “”... и блиЗкий Cynanchum scandens Эндемичный вид С. rossicum ”, meaning “... and the endemic species Cynanchum rossicum [which is] closely related to C. scandens ”). As we can see, it is almost exactly the same wording as in Kleopow’s unpublished dissertation (in which, however, the genus Vincetoxicum was accepted; see above). However, there is one important difference: there is no indication of the authorship and no other indirect reference. The article by Kleopow (1929) is cited in the general list of references at the end of his 1941 article, on page 251 of the book, but there is no link between the name on page 215 and the reference on page 251. Thus, in our opinion, it cannot be reliably regarded as indirect reference as defined by Art. 38.14 and 41.3 and Glossary of the ICN ( McNeill et al. 2012). The same opinion was expressed by Werner Greuter and Kanchi Gandhi (personal communications in email messages to Sergei Mosyakin).

Fedtschenko (1941: 582) explicitly accepted “ Cynanchum rossicum Kleop. ” as a distinct species but at the same time cited “ Vincetoxicum Schmalhausenii Litw. , V. medium auct.” as its synonyms. Thus, if we assume that Fedtschenko was the first author who validated the name C. rossicum , we should conclude that he simultaneously made that name illegitimate by inclusion of an earlier valid name of another species ( V. schmalhausenii ) in synonymy.

However, is it possible that the name C. rossicum was validated before 1941?