(2703) Proposal to conserve the name Tontelea attenuata against Maytenus amygdalina (Celastraceae)

Abstract

(2703) Tontelea attenuata Miers in Trans. Linn. Soc. London 28: 384. 17 May–8 Jun 1872 [Angiosp.: Hippocrat. / Celastr.], nom. cons. prop. Typus: Brazil, [Amazonas], “Secus Rio Negro, Brasiliae septentrionalis, inter Barcellos et San Isabel”, Dec 1851, Spruce 1927 (K barcode K000529979). (=) Maytenus amygdalina Turcz. in Bull. Soc. Imp. Naturalistes Moscou 31(1–2): 451. Sep–Oct 1858, nom. rej. prop. Holotypus: [Guyana (or northern Brazil)] “Brit. Guiana”, “Maytenus amygdalinus Turcz.”, “1837, &c.”, Schomburgk 656 [959?] (KW barcodes KW001001094 & KW001001095). Maytenus amygdalina Turcz. (in Bull. Soc. Imp. Naturalistes Moscou 31(1–2): 451. 1858 [‘amygdalinus’]) was described by Turczaninow based on a specimen collected by R.H. Schomburgk that is now deposited in KW. The specimen is mounted on two sheets with two different barcodes (KW001001094 and KW001001095; images available from https://plants.jstor.org/stable/10.5555/al.ap.specimen.kw001001094 and https://plants.jstor.org/stable/10.5555/al.ap.specimen.kw001001095). These two sheets are cross-referenced in pencil as “Sheet 1” and “Sheet 2”, respectively. The original label, with “Maytenus amygdalinus” in Turczaninow's handwriting, is mounted on the first sheet, while the second sheet has a photocopy of the original label. The cross-referencing pencil notes were most probably added by the curatorial staff of KW in the 1980s (or the late 1970s) when the specimen was mounted. The photocopy of the original label was made probably at the same time. In the original Turczaninow collection the two branches were most probably kept unmounted in one folder, with just one original label, which is a common situation with many other Turczaninow's specimens. Following Art. 8.2 (and its Ex. 4) and Art. 8.3 of the ICN (Turland & al. in Regnum Veg. 159. 2018), KW001001094 and KW001001095 should be considered one specimen mounted on two sheets. It is evident that almost all new taxa described by Turczaninow in his “Animadversiones” (published in five issues of Bull. Soc. Imp. Naturalistes Moscou in 1854–1855, 1858–1859, and 1863; for complete bibliography see Stafleu & Cowan in Regnum Veg. 115: 541. 1986) were based, unless noted otherwise, on specimens from his personal herbarium, which he donated in the late 1840s to the Imperial Khar'kov [Kharkiv] University (now the V.N. Karazin National University of Kharkiv, CWU). It is properly reflected in the title of his article, in which the name M. amygdalina was validated: “Animadversiones in secundam partem herbarii Turczaninowiani, nunc Universitatis Caesareae Charkowiensis”. The Turczaninow historical collection is now deposited at the National Herbarium of Ukraine in Kyiv (KW), to which it was transferred from CWU at the end of World War II (for history of the Turczaninow Herbarium, see Mosyakin & al. in Phytotaxa 334: 49–54. 2018, and references therein). Consequently, the specimen mounted on two sheets at KW (see above) should be considered the holotype (Art. 9.1 of the ICN; see also McNeill in Taxon 63: 1112–1113. 2014). Thus, lectotypification of the name Maytenus amygdalina by Savinov (in Novosti Sist. Vyssh. Rast. 37: 295. 2005) was unnecessary. In addition to the Schomburgk specimen, Savinov (l.c.) cited (as “Galeottiana Mexicana prope Jalappa lecta n. 7017”) another collection or specimen mentioned in the protologue of M. amygdalina. However, his citation of the supposedly second original specimen is based on a misunderstanding. The specimen from Mexico is not part of the original material of M. amygdalina—Turczaninow simply compared his new species to another specimen with not yet fully opened flowers collected by Galeotti and concluded that they were different (“Huic affinis est sed diversa species Galeottiana Mexicana prope Jalappa lecta n. 7017 e specimine floribus non omnino expansis mihi nota”). The collection Galeotti 7017 is also erroneously indicated as the type of M. amygdalina in the Tropicos database (http://www.tropicos.org/Name/50224439; all online resources accessed 14 Mar 2019). The specimen of Galeotti at KW (Turczaninow Herbarium) most probably belongs to Zinowiewia integerrima (Turcz.) Turcz. (in Bull. Soc. Imp. Naturalistes Moscou 32(1–2): 276. 1859 ≡ Wimmeria integerrima Turcz., l.c. 1858: 451), a species described by Turczaninow also from Mexico, but based on another specimen that was collected by Linden (holotype KW001001101; image available from https://plants.jstor.org/stable/10.5555/al.ap.specimen.kw001001101). For a long time the name Maytenus amygdalina was almost completely forgotten and its real taxonomic identity remained uncertain. To the best of our knowledge, the name was listed only by C. Mueller (in Ann. Bot. Syst. 7: 579. 1868) and not accepted in other taxonomic publications. Turczaninow stated in the protologue that the species has opposite leaves and corymbose inflorescences, a combination of characters not present in Maytenus Molina, and because of that the name was excluded from the revision of Neotropical Maytenus by Biral (Sistemática e Filogenia de Maytenus (Celastraceae) na Região Neotropical [Ph.D. Thesis]. 2016; available from https://repositorio.unesp.br/bitstream/handle/11449/141965/santos_lb_dr_rcla_int.pdf). It is listed as an unresolved or unplaced name in the Plants of the World Online (http://www.plantsoftheworldonline.org/taxon/urn:lsid:ipni.org:names:161806-1), The Plant List (http://www.theplantlist.org/tpl1.1/record/kew-2360118), and some other taxonomic databases. Recently two of us (LB & JAL) studied the high-resolution digital images of KW001001094 and KW001001095 provided by KW and concluded that Turczaninow's species is conspecific with Tontelea attenuata Miers (in Trans. Linn. Soc. London 28: 384. 1872); see the lectotypification note below. Mennega (in Taxon 38: 505. 1989) designated Spruce 1927 as the lectotype of T. attenuata but it constituted only a first-step lectotypification (Art. 9.17 of the ICN) because she did not indicate in which herbarium the lectotype was deposited. Lombardi (in Brittonia 58: 55. 2006, in Fl. Neotrop. Monogr. 114: 159. 2014) cited as the lectotype a specimen from K but without specifying one of the two available duplicates (K000529978 and K000529979). As this was a designation that referred to a single gathering but to more than one specimen (Art. 9.17 of the ICN) it represents a second-step lectotypification, but as it was not of a single specimen (Art. 8.1 of the ICN) a third-step is desirable and so we designate here as the lectotype of Tontelea attenuata Miers the specimen: Brazil: [Amazonas] “Secus Rio Negro, Brasiliae septentrionalis, inter Barcellos et San Isabel”, Dec 1851, R. Spruce 1927 (K barcode K000529979; image available at http://apps.kew.org/herbcat/detailsQuery.do?barcode=K000529979). A search in JSTOR Global Plants (https://plants.jstor.org) and some other databases for possible isotypes of Maytenus amygdalina demonstrated that other specimens that are probably parts of the same gathering are known in several herbaria, such as BM, G, K, L, P, W, etc.; some of them are incompletely labelled (see below). Moreover, it looks as if the types of Maytenus amygdalina and Tontelea longifolia Miers (l.c.: 384; lectotype from K designated by Lombardi, l.c., 2006: 55, and cited as “Brazil. Amazonas: Rio Negro [incorrectly given as ‘Guiana anglica’ on F Neg 13348 (ex B, destroyed)], 1840, R.H. Schomburgk 959”) most probably belong to the same gathering of Schomburgk made in the late 1830s (1837?) or 1840. However some specimens from BM, G, K, L, and P are undated. The KW specimen dated as “Coll. 1837, &c.” (meaning 1837 and/or subsequent years) is numbered, most probably due to a transcription error, with the handwritten “656” instead of “959”, which is the number of all other known numbered original specimens of T. longifolia. Missing, incomplete, and/or confusing label information, especially concerning dates and geographical localities, is often a problem with Schomburgk's specimens (see Van Dam in Jansen-Jacobs, Fl. Guianas, Suppl. Ser., 3: 1–211. 2002; Alexander in Da Silva & al., Contr. Study Biol. Divers. 4: 79–84. 2014) and because of that it is difficult to judge if all the mentioned specimens of Schomburgk indeed belong to the same gathering. In any case, morphologically they are all very similar, and T. longifolia is now considered a synonym of T. attenuata (see Lombardi, l.c. 2006, l.c. 2014). There is now virtually no doubt that Maytenus amygdalina and Tontelea attenuata are conspecific and the first name has priority. Thus, a new combination in Tontelea Miers based on M. amygdalina is required by the ICN. However, that nomenclatural action would result in the replacement of a widely accepted name, T. attenuata, with an unfamiliar new name, a combination based on a long-forgotten basionym. Moreover, T. attenuata is the conserved type of the generic name Tontelea (see Mennega, l.c., and Brummitt in Taxon 42: 692. 1993) and reducing that species name to synonymy is not desirable. Tontelea attenuata is one of the commonest and best-known species of the genus, occurring in the Amazonian forests and savannahs in Brazil, Bolivia, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela (Lombardi, l.c. 2014). The name is accepted in many taxonomic publications and databases (e.g., Smith in Brittonia 3: 474. 1940; Talbot [in Brako & Zarucchi, Cat. Fl. Pl. Gymnosp. Peru] in Monogr. Syst. Bot. Missouri Bot. Gard. 45: 568. 1993; Görts-van Rijn & al. [in Funk & al., Checklist Pl. Guiana Shield] in Contr. U.S. Natl. Herb. 55: 314. 2007; Görts-van Rijn & Mennega in Hokche & al., Nuevo Cat. Fl. Vasc. Venez.: 417. 2008; Lombardi in Rodriguésia 61: 124. 2010 & l.c. 2014: 159; Grandtner & Chevrette, Dict. Trees. 2 [S. Amer.]: 667. 2013; Liesner [in Jørgensen & al., Cat. Pl. Vasc. Bolivia] in Monogr. Syst. Bot. Missouri Bot. Gard. 127: 501. 2015; Ulloa Ulloa & al. in Science 358: [Data Set S1] 757. 2017; Plants of the World Online: http://www.plantsoftheworldonline.org/taxon/urn:lsid:ipni.org:names:162852-1; World Flora Online: http://sweetgum.nybg.org/science/world-flora/taxon.php?irn=127958; The Plant List: http://www.theplantlist.org/tpl1.1/record/kew-2430963; see also the references above). In earlier literature the species was sometimes recognized as Salacia attenuata (Miers) Peyr. (in Martius, Fl. Bras. 11: 149. 1878; Macbride [in Fl. Peru] in Field Mus. Nat. Hist., Bot. Ser. 13 (part 3A, no. 1): 210. 1951, etc.). A name change for a generally accepted tropical South American species, the conserved type of Tontelea, in favor of an unfamiliar new combination based on a long-forgotten name will not serve nomenclatural stability. Because of that we propose here to conserve the currently accepted name Tontelea attenuata against the earlier name Maytenus amygdalina under Art. 14 of the ICN. LB, https://orcid.org/0000-0003-2493-8514 SLM, https://orcid.org/0000-0002-3570-3190 JAL, https://orcid.org/0000-0003-1716-3159 We are grateful to John McNeill (Royal Botanic Garden, Edinburgh, Scotland, U.K. & Royal Ontario Museum, Toronto, Ontario, Canada) for his valuable advice on nomenclature and for his editorial comments, and to John Wiersema (Department of Botany, Smithsonian Institution, Washington, D.C., U.S.A.) for several editorial improvements. The kind assistance of Natalia M. Shiyan (Head Curator of KW, M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, Kyiv, Ukraine) and Tetiana S. Karpiuk (formerly KW, now WWF – Ukraine team, Kyiv, Ukraine) is greatly appreciated.