(2784) Proposal to reject the name <i>Maytenus tovarensis</i> (<i>Celastraceae</i>)

(2784) Maytenus tovarensis Radlk. in Sitzungsber. Math.-Phys. Cl. Königl. Bayer. Akad. Wiss. München 8: 383. Jul–Dec 1878 [Angiosp.: Celastr.], nom. utique rej. prop. Holotypus: Venezuela, [Aragua], Colonia Tovar, [1847?], Karsten (B [destr.]). Maytenus tovarensis Radlk. (in Sitzungsber. Math.-Phys. Cl. Königl. Bayer. Akad. Wiss. München 8: 383. 1878) was named based on a collection gathered by H. Karsten from Colonia Tovar, Venezuela, probably in 1847 (Tryon in Taxon 12: 104. 1963) and deposited in B. This specimen was presumably lost in the bombing of Berlin in WWII, and no duplicates have been located. In the original description, M. tovarensis is compared to Sapindaceae genera and the genus Schieckea H. Karst. (in Bot. Zeitung (Berlin) 6: 398–399. 1848), described with no species included, considered as a synonym: “23 Schieckea Karsten in Bot. Zeit. VI, 1848, p. 398 = Maytenus tovarensis Radlk.” (Radlkofer, l.c.: 312, 383). Subsequently, the species was again mentioned with Schieckea as synonym by Peter (in Bot. Jahresber. (Just) 6(2): 189. 1878). The combination of characters of inflorescence and fruit, described in the protologue respectively as “paniculae subracemiformes (ramis brevibus paucifloris) solitariae vel ternae” and “capsula e globoso trigona … trilocularis … abortu monosperma” (Radlkofer, l.c.: 383), is typical of the genus Celastrus. On the other hand, these characters in combination are not found in the genus Maytenus Molina nor in the genera that were later segregated from it, such as Monteverdia A. Rich. and Tricerma Liebm. Also, Radlkofer (l.c.) commented on the scandent habit of the specimen in the protologue, according to him annotated by Karsten on the label as “frutex scandens”. Celastrus species are typically scandent, while Maytenus and related genera are represented by erect plants. Three-valved fruits with only one seed due to abortion, as described in the protologue of M. tovarensis, are characteristic of Celastrus subg. Racemocelastrus, described by Ding Hou (in Ann. Missouri Bot. Gard. 42: 277. 1955) to comprise all Neotropical species exclusively. Maytenus tovarensis was first associated with the genus Celastrus by Loesener (in Engler & Prantl, Nat. Pflanzenfam. III(5): 205. 1892), but without proposing a taxonomic resolution: “C. monosperma Roxb. aus Ostindien, mit besonders in den ♂ Exemplaren sehr großen, weitverzweigten Blütenrispen u. a. Letzterer Art steht die tropisch-amerikanische, bisher als Maytenus tovarensis Radlk. bekannte Art sehr nahe, deren systematische Stellung ohne Bl. nicht entschieden werden kann.” Subsequently, M. tovarensis was formally stated to be a synonym of the new combination C. racemosus (Reissek) Loes., based on M. racemosa Reissek (in Martius, Fl. Bras. 11(1): 30. 1861), by Loesener (in Engler & Prantl, Nat. Pflanzenfam. III(5): 459. 1896): “Celastrus racemosa [Reiss.] Lös. = Maytenus racemosa Reiss. = M. tovarensis Radlk.” Loesener reaffirmed this synonymy in three subsequent publications (in Engler & Prantl, Nat. Pflanzenfam. Nachtr. II–IV: 222. 1897; in Bot. Jahrb. Syst. 24: 199. 1898; in Engler & Prantl, Nat. Pflanzenfam., ed. 2, 20b: 134. 1942). However, C. racemosus (Reissek) Loes. is an illegitimate later homonym of C. racemosus Turcz. (in Bull. Soc. Imp. Naturalistes Moscou 36(1, 1): 599. 1863). Despite the illegitimacy of Celastrus racemosus (Reissek) Loes., Urban (Symb. Antill. 5: 52. 1904) considered it as a correct name, with the older Maytenus tovarensis and Schieckia as synonyms, and described the new variety C. racemosus var. trinitensis Urb. (l.c.). However, neither Loesener nor Urban, both of whom worked in Berlin, mentioned having analyzed or seen the type specimen of M. tovarensis, which, at that time, was in the Berlin collection. Several subsequent publications also accepted the illegitimate C. racemosus (e.g., Williams, Fl. Trinidad 1: 173. 1930; Pittier in Bol. Soc. Venez. Ci. Nat. 3: 424. 1937; Ding Hou, l.c.: 278), but none included M. tovarensis as a synonym. The inflorescence type of Maytenus tovarensis described in the protologue is very similar to that of Celastrus liebmannii Standl. (in Publ. Field Mus. Nat. Hist., Bot. Ser. 8: 316–317. 1931), which is the current name most commonly used for C. racemosus (Reissek) Loes., and which occurs in Venezuela (Ding Hou, l.c.: 280–281). The inflorescence is an axillary paniculiform cyme, compound with the secondary branches ending in a solitary flower or in a simple dichasium of three flowers. Thus, it is likely that M. tovarensis is in fact synonymous with C. liebmannii. Some authors have considered C. racemosus and C. liebmannii Standl. as heterotypic synonyms of C. grenadensis Urb. (l.c.: 51) (e.g., Bornstein in Howard, Fl. Lesser Antilles 5(2): 177. 1989; Whitefoord in J. Arnold Arbor. 70: 144. 1989; Acevedo-Rodríguez & Strong, Catal. Seed Pl. West Indies [Smithsonian Contr. Bot. 98]: 215. 2012). The type of C. grenadensis has not been located, and was also presumably lost in the bombing of Berlin. Ding Hou (l.c.: 285) treated C. grenadensis as a doubtful species due to the lack of type material and the insufficient description. Pittier published C. meridensis Pittier (l.c.: 424–425), a second congeneric species from Venezuela, and compared it with C. racemosus based on morphological characters, distinguishing each by their inflorescence: C. meridensis has sessile to subsessile flowers, while C. racemosus has flowers with pedicels longer than 1 mm. Pittier (l.c.) pointed out that Karsten had collected C. racemosus in Colonia Tovar, probably referring to the M. tovarensis type collection, although not mentioning this name or any specimen. Nevertheless, because the inflorescence type in the New World Celastrus species has been reported as an inconstant character (Molina-Paniagua & Lorea-Hernández in Rotter & Rzedowski, Fl. Bajío 171: 1–42. 2011), the precise taxonomic identity of M. tovarensis remains unclear. Maytenus tovarensis is a long-forgotten name, with the most recent mentions being found in Urban (l.c.) and Loesener (l.c. 1942). Subsequent publications do not mention the name, including the revised catalogue of the Venezuelan flora (Hokche & al., Nuevo Catál. Fl. Vasc. Venez.: 321. 2008). The apparent loss of the type specimen makes difficult further comparisons and the precise application of the name. However, its description indicates an unambiguous association with the genus Celastrus, yet the name M. tovarensis antedates all the above-mentioned Neotropical Celastrus species. Thus, if conspecific with any one of these Neotropical Celastrus, which seems assured, the name M. tovarensis would have priority and a new combination would be required, which will not serve nomenclatural stability. Instability will arise because C. liebmannii is widely distributed in the Neotropics, from Mexico to Brazil, and is cited as such in many floras and checklists (e.g., Liesner in Jørgensen & León-Yánez, Cat. Pl. Vasc. Ecuador [Monogr. Syst. Bot. Missouri Bot. Gard. 75]: 393. 1999; Lombardi & Groppo in Forzza & al., Catál. Pl. Fung. Brasil 1: 842. 2010; Liesner in Jørgensen & al., Cat. Pl. Vasc. Bolivia [Monogr. Syst. Bot. Missouri Bot. Gard. 127]: 497. 2014; Barrie in Davidse & al., Fl. Mesoamer. 2(3): 212. 2015; Villaseñor in Revista Mex. Biodivers. 87: 696. 2016; Baksh-Comeau & al. in Phytotaxa 250: 147. 2016; Ulloa Ulloa & al. in Science 358: [Data Set S1] 750. 2017). The above arguments have demonstrated currently unresolvable doubt as to the precise identity of Maytenus tovarensis. Because any rediscovery of type material or neotypification of this name will almost certainly necessitate a new combination in Celastrus, based on this unfamiliar name, that will not serve nomenclatural stability, it is proposed that the name M. tovarensis be rejected under Art. 56 of the ICN (Turland & al. in Regnum Veg. 159. 2018). LB, https://orcid.org/0000-0003-2493-8514 I am grateful to John Wiersema (Department of Botany, Smithsonian Institution, Washington, D.C., U.S.A.) and John McNeill (Royal Botanic Garden, Edinburgh, Scotland, U.K. & Royal Ontario Museum, Toronto, Canada) for reviewing the manuscript and for editorial comments, and to James J. Roper for reviewing the English.

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