(3041) Proposal to conserve the name Erythroxylum suberosum against Steudelia brasiliensis (Erythroxylaceae)

(3041) Erythroxylum suberosum A. St.-Hil., Pl. Usuel. Bras.: t. 69, fig. A. 4 Aug 1828 [Angiosp.: Erythroxyl.], nom. cons. prop. Typus: Brazil, "Prov. de Minas Geraes" [Minas Gerais], "Corgo do Mathias", 1819, Saint-Hilaire C1-617 (P barcode P00723716 [F neg. no. 35187]!; isotypi: MPU barcode MPU012224!, P barcodes P00723717! & P00723718!). (=) Steudelia brasiliensis Spreng., Neue Entd. 3: 59. 1822, nom. rej. prop. Neotypus (hic designatus): Brazil, Sellow (K barcode K000996436!). The pantropical genus Erythroxylum P. Browne encompasses approximately 250 species, with Brazil alone accounting for 158 recorded species (Costa-Lima & Chagas in Bol. Soc. Argent. Bot. 56(Supl.): 140–141. 2021). Interestingly, the first name for a Brazilian species of Erythroxylaceae Kunth was not coined under Erythroxylum, nor even originally under Erythroxylaceae. This was Steudelia brasiliensis Spreng., a genus and species described by Sprengel (Neue Entd. 3: 59. 1822) under "Büttnereae" (Byttneriaceae). Shortly thereafter, this same author (Sprengel, Syst. Veg. 2: 391. 1825) recognized S. brasiliensis as belonging to Erythroxylaceae and synonymized it under Erythroxylum havanense Jacq., possibly due to the congruent leaf blade morphology. Some years later, Martius (Beitr. Erythroxylon: 97. 1840) also recognized Steudelia brasiliensis as belonging to Erythroxylaceae, including it as synonym of Erythroxylum suberosum A. St.-Hil, a name published by Saint-Hilaire (Pl. Usuel. Bras. 1: t. 69, fig. A. 1828) and typified as cited above by Plowman (in Supl. Acta Amazon. 14(1/2): 142. 1984). Other authors who prepared significant monographs on Erythroxylaceae (e.g., Peyritsch in Martius, Fl. Bras. 12(1): 170. 1878; Schulz in Engler, Pflanzenr. IV. 134 (Heft 29): 27. 1907) also adopted the Martius (l.c. 1840) synonymization. However, the name proposed by Sprengel (l.c. 1822) has priority over Saint-Hilaire's (l.c.) name, in accordance with Principle III and Art. 11 of the International Code of Nomenclature for algae, fungi, and plants (ICN; Turland & al. in Regnum Veg. 159. 2018). Sprengel (l.c. 1822) did not cite the collection upon which he based the description of Steudelia brasiliensis, but it is likely that it was some collection by F. Sellow. Sellow collected in Brazil from 1817 to 1831 (Urban in Bot. Jahrb. Syst. 17: 177–198. 1893), and some of his specimens were cited by Sprengel (l.c. 1825) to describe other Brazilian plants. Furthermore, according to Urban (in Bot. Jahrb. Syst. 14, Beibl. 32: 38. 1891), among the collections that comprised Sprengel's original herbarium was that of Sellow, one of the few who collected in Brazil at that time. It is highly likely that the original material used by Sprengel to describe S. brasiliensis no longer exists. According to Stafleu & Cowan (in Regnum Veg. 112: 806. 1985), a large part of Sprengel's collection was acquired by Karl Müller in Halle and, in 1890, purchased by the Berlin Herbarium (B). After the fire at the Berlin Herbarium, due to the bombing on March 1st, 1943, during World War II, the only specimen of Erythroxylum collected by F. Sellow currently deposited in B is an isolectotype of E. umbu Costa-Lima, a substitute name for E. microphyllum var. amplifolium Mart.; all other Erythroxylaceae specimens originally deposited there before 1943 were destroyed. Schulz (l.c.), who worked at B, cited the collections Sellow 210, 5086, and 5143 as being E. suberosum, but none of them were seen by me in other herbaria. Possibly one of these – or even all – may have been analyzed by Sprengel (l.c. 1822). Due to the lack of strong evidence regarding the original material used by Sprengel to describe S. brasiliensis or if it exists, we selected a specimen collected by F. Sellow deposited at K as a neotype for the name S. brasiliensis. This specimen is an excellent match to the diagnosis provided by Sprengel (l.c. 1822). Although older, the name Steudelia brasiliensis fell into oblivion and is rarely mentioned in botanical literature, being referred to only as a synonym (see Martius, l.c. 1840; Steudel, Nomencl. Bot., ed. 2: 597. 1840; Peyritsch, l.c.; Schulz, l.c.). Unlike S. brasiliensis, the name Erythroxylum suberosum has been widely used in Brazil since its publication and has been adopted in the main taxonomic treatments of Erythroxylaceae (e.g., Martius, l.c. 1840; Peyritsch, l.c.; Schulz, l.c.) and in the most important floristic studies on and checklists of Brazilian plants (e.g., Barbosa & al., Checkl. Pl. Nordeste Brasil. 2006; Forzza & al., Cat. Pl. Fung. Brasil 2. 2010; Brazil Flora Group in Rodriguésia 66: 1085–1113. 2015 & 69: 1513–1527. 2018, in Taxon 71: 178–198. 2022). In addition to the literature cited, as far as we could ascertain, the name S. brasiliensis had also not been applied to any herbarium specimens. For example, in a search on 21 April 2024, in SpeciesLink (CRIA, https://specieslink.net) and in Herbário Virtual REFLORA (REFLORA, https://floradobrasil.jbrj.gov.br/reflora/herbarioVirtual/), the two main databases with plant specimens from Brazil, the name E. suberosum is retrieved with 3600 and 1871 records, respectively. However, for the name S. brasiliensis, no records were found. Because of the astringent properties of the bark of this species, the name Erythroxylum suberosum has been attributed to it since the 19th century, where it is reported in the literature as a medicinal plant and useful for the tanning and dyeing industry (e.g., Saint-Hilaire, l.c.; Martius, Syst. Mat. Med. Bras.: 51. 1843). In recent decades, this name has also been associated with studies that have detected or confirmed some other properties of this species, such as antimicrobial, antioxidant, and anticancer activities (e.g., Violante & al. in Brazil. J. Microbiol. 43: 1302–1308. 2012; Oliveira & al. in Res. J. Phytochem. 9: 68–78. 2015; Macedo & al. in Brazil. Dental J. 27: 108–112. 2016). Considering the arguments mentioned above, we propose the conservation of the name Erythroxylum suberosum over the name Steudelia brasiliensis to maintain nomenclatural stability. We are grateful to John McNeill and John Wiersema for their valuable comments, which have improved this proposal. This paper is part of the Ph.D. thesis of the first author entitled Systematics of the Brazilian coca plants (Erythroxylum, Erythroxylaceae), supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES (finance Code 001 and process No. 88881.135723/2016-01) and Fundação Flora de Apoio à Botânica/Instituto de Pesquisas Jardim Botânico do Rio de Janeiro.