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 : 79-80

Validation of Cynanchum rossicum in 1933?

Following the recommendation of Werner Greuter (personal communication, email message of 29 July 2016 to Sergei Mosyakin), the first author of the present article consulted the Index Kewensis Supplements and found that the name Cynanchum rossicum Kleopow was listed in Supplement 8 ( Hill 1933: 67) with a full reference to the protologue but without any indication of its provisional status. For comparison, the next entry following C. rossicum is “[C.] Savatierii, Koidz. ”, for which Hill clearly indicated that it was originally published as a synonym (“in syn.”) and cited after a colon another name of an uncertain status (supposedly accepted name? a synonym or replaced name?), “ Tylophora Maximowiczii ”.

Indeed, validation of a name in Index Kewensis supplements can be viewed as somewhat doubtful because some authors argued that it does not indicate explicit acceptance. However, Greuter (1985) specially studied that problem and concluded that validations of names in Index Kewensis supplements , even those published after Supplement 3, should be accepted. In that conclusions he challenged the opinion of Meikle (1971: 297), who noted that “…the 4 th Supplement became a straightforward Index , giving the names and references to all validly published generic and specific names of flowering plants, without passing taxonomic judgments or attempting to tell us which name is to be maintained, and which discarded. This non-committal objectivity has been consistently maintained since 1913…”. Greuter (1985) specially indicated that, among other categories of names expected to be first validated in Index Kewensis and its supplements, provisional names (even those validated “by inadvertence”) are obvious candidates. Greuter’s opinion was recently opposed by Sennikov et al. (2015), which is discussed below.

Since the present version of the Code ( McNeill et al. 2012) does not explicitly rejects validations made in Index Kewensis and its supplements, in other indexes and/or similar publications, and there is no internal indication of the non-acceptance of the name by Hill, we accept here the expert opinion of Greuter (1985) and conclude that the name C. rossicum was cited as technically accepted and thus validated (probably inadvertently) already in 1933. According to Art. 46 Note 2 of ICN, the authorship of the name should be attributed to Kleopow and not to Hill as the compiler of Supplement 8 of Index Kewensis.

The combination “ C. rossicum (Kleopow) Borhidi ” proposed in Borhidi & Priszter (1966: 245) and sometimes accepted in recent literature (e.g., Kartesz 1999; Darbyshire et al. 2000; DiTommaso et al. 2005; Kricsfalusy & Miller 2008; etc.) is thus superfluous. In fact, Borhidi probably has not seen the protologue, since he assumed that Kleopow in 1929 published his new species as Vincetoxicum (not Cynanchum ) rossicum , and did that validly (not as a provisional name).

The name V. rossicum should be thus regarded as a new combination made by Barbaricz (1950) by indirect reference, with the correct authorship as cited below.

Vincetoxicum rossicum (Kleopow) Barbaricz (1950: 346; validated by indirect reference [Art. 38.14 of ICN] to the description of Cynanchum rosscum Kleopow 1929 , nom. inval., nom. provis.; and by indirect reference [Art. 41.3 of

ICN] to the existing basionym Cynanchum rosscum Kleopow in Hill 1933) ≡ Cynanchum rossicum Kleopow (in Hill

1933: 67) [ Cynanchum rossicum Kleopow 1929: 67 , nom. inval., nom. provis.].

Type (neotype, designated by Fedoronchuk in Fedoronchuk et al. 2006: 782):— UKRAINE: [Dnipro (formerly Dnipropetrovsk and Ekaterinoslav) Region/Oblast’] “Е[кaтеpинo]слав. Ap. H. Boйнов” (KW!, from Czernjaëv memorial collection).

Note on typification. Kleopow (1929) mentioned on page 68 of the protologue five specimens (“specim. exam.”, syntypes) and indicated that specimens 1–2 (collected in “Prov. Charkov ”— Kharkiv Region /Oblast’, Ukraine) are from the Herbarium of the Kharkiv Botanical Garden (of Kharkiv University, now part of CWU); one specimen (No. 3, collected in “Prov. Tanaitica” on the Medveditsa River, a tributary of the Don River—now probably in Volgograd Region /Oblast’ of Russia) is from D.I. Litvinov’s herbarium, and specimens 4–5 (collected in “Prov. Saratov ” in Sarepta—now part of the city of Volgograd, Russia) are deposited in the herbarium of the “ Kiev Botanical Institute” (now part of KW). On page 67 he indicated that the species “Habitat in decliviis inter frutices in Ucrania orientali atque in Rossia australi (nec non media?)”. In that phrase he simply reported a presumable general range and habitats of the new species, not any particular specimens. However, Fedoronchuk et al. (2006: 782) cited that phrase, stated that the corresponding specimens are absent in KW (presumably lost or destroyed), and selected the neotype. Main collections of Kleopow are deposited in KW ( Krytzka & Mosyakin 2002; Shiyan 2011); however, our additional extensive search at KW and CWU for any syntypes cited in the protologue also failed to recover any corresponding specimens in these collections. There are some chances that at least one syntype might be still present among herbarium collections of Litvinov; in that case that specimen (and/or other syntypes, if found) can be qualified for being selected as a lectotype, which will take precedence over the neotype (Art. 9.13 of ICN: McNeill et al. 2012).

Kriczfalusy & Miller (2008: 23–24) further commented on the type of the species: “The neotype (that is two plants mounted on one herbarium sheet) is originally from Ekaterinoslav gubernija of the Russian Empire (nowadays Dnipropetrovsk oblast of Ukraine) where one plant, with flowers, was collected by Vojnov in 1853 under the name V. medium Decaisne , and next one, with fruits, by Colchigin under name V. nigrum Moench. This neotype of C. rossicum was published only recently in typification of species of vascular plants described from Ukraine ( Fedoronchuk et al. 2006). However, a valid type specimen can only be made from a single plant.” By the last sentence they probably doubted the validity of the neotype selected by Fedoronchuk. However, Fedoronchuk clearly indicated as the neotype only one of the two plants mounted on the same herbarium sheet. Consequently, until any syntype suitable for lectotypification is found, the neotype selected by Fedoronchuk should stand.