BYTEBIER, B. (2025). The correct name for the type species of the genus Benthamia (Habenariinae, Orchidaceae). Candollea 80: 1–5. In English, English abstract. DOI: http://dx.doi.org/10.15553/c2025v801a1
Louis-Marie Aubert Aubert Du Petit-Thouars (1758–1831) was one of the first botanists to describe several orchids, collected on the Mascarenes and Madagascar, in a seminal work published in 1822. Besides Linnean binomials, Du Petit-Thouars proposed alternative (Thouarsian) names that should be taken into consideration in certain nomenclatural situations, since they are proper binomials. One of the newly proposed species was Satyrium latifolium Thouars with the alternative Thouarsian name Satorkis latisatis Thouars. However, the former name is a later homonym and thus illegitimate. When Sprengel transferred the species to Habenaria Willd., the epithet latifolia was unavailable because of the existence of a previous homonym, and he coined the replacement name H. chlorantha Spreng., whereas he should have used the Thouarsian epithet latisatis. Lastly, Garay & Romero transferred the Sprengel name to the genus Benthamia A. Rich, which has hitherto been treated as the accepted name for this species and is furthermore the type species of the genus. However, in view of the fact that this is an illegitimate superfluous name, the correct binomial is proposed here as B. latisatis (Thouars) Bytebier.
Introduction
Louis-Marie Aubert Aubert Du Petit-Thouars (1758–1831) was one of the first botanists to collect plants on the Mascarene Islands and Madagascar (Stafleu & Cowan, 1976). In a seminal work Histoire particulière des plantes Orchidées recueillies sur les trois îles australes d'Afrique, de France, de Bourbon et de Madagascar, Du Petit-Thouars (1822) described and illustrated 91 orchid species gathered during his travels in the region. Remarkably, apart from using traditional Linnean names, Du Petit-Thouars included alternative names for his species in a self-designed (Thouarsian) nomenclatural system. He originally introduced this alternative system in a paper read to the Societé Philomatique de Paris and published in 1809 (Du Petit-Thouars, 1809). In essence, he proposed to include a reference to the family in the genus name, and a reference to the genus in the species epithet. These alternative Thouarsian names caused considerable nomenclatural confusion until Friis & Rasmussen (1975) clarified their interpretation and pointed out that the alternative Thouarsian names are proper binomials, which are therefore admissible under the International Code of Nomenclature for algae, fungi and plants (Turland et al., 2018). Although the Thouarsian nomenclatural system never caught on, some generic names are still in use, such as for instance Cynorkis Thouars and Corymborkis Thouars. Friis & Rasmussen (1975: 313) furthermore concluded that the alternative Thouarsian names should be considered as synonyms “which are to be taken into consideration (1) in case the traditional name has an earlier homonym or (2) if the traditional epithet is going to be used in a new combination, and the resulting binary combination is a later homonym”.
The genus Benthamia A. Rich. was established by Achille Richard in 1828 for two species, Benthamia latifolia A. Rich., based on Satyrium latifolium Thouars, and a newly described species, Benthamia spiralis A. Rich. (Richard, 1828). Pridgeon et al. (2001) selected the former species as the lectotype for the genus. Benthamia is endemic to Madagascar, Mauritius and Réunion. As currently understood, it consists of 32 species but is in dire need of revision as it is clearly not monophyletic (Ngugi et al., 2020). However, Satyrium latifolium Thouars is illegitimate because it is a later homonym of Satyrium latifolium L. [in Fl. Jamaic.: 20 (1759)], which itself is a superfluous name for Satyrium plantagineum L. [in Syst. Nat., Ed. 10, 2: 1244 (1759)], now called Microchilus plantagineus (L.) D. Dietr.
When Sprengel (1826) transferred the taxon to Habenaria, the epithet latifolia was unavailable because of the existence of a previous homonym by Kunth (1816), and thus he coined the replacement name H. chlorantha. Nevertheless, several later authors still transferred the illegitimate Thouars name Satyrium latifolium to other genera, leading to names that should be treated as replacement names (Turland et al., 2018: ICN Art. 6.10, 6.11, 58.1) that are illegitimate (ICN Art. 52.1). Recently, Garay & Romero (1998) transferred the Sprengel epithet to the genus Benthamia as B. chlorantha, which is currently the accepted name for this species and is furthermore the type species of the genus (see POWO [ https://powo.science.kew.org]). However, Sprengel should have used the earliest available (Thouarsian) epithet latisatis instead of using the epithet chlorantha for his new combination in Habenaria. Sprengel's name is therefore regarded as a superfluous replacement name. Likewise, Garay & Romero's name in Benthamia is a superfluous illegitimate name.
Consequently, the new combination Benthamia latisatis (Thouars) Bytebier is made below, along with the citation of its type and full homotypic synonymy. This is only the second Thouarsian epithet that forms part of a correct binomial, the first one being corymbis in Corymborkis corymbis Thouars.
Taxonomy
Benthamia latisatis (Thouars) Bytebier, comb. nov.
≡ Satorkis latisatis Thouars, Hist. Orchid.: premier tableau des espèces d'orchidées 1re section Satyrions, tab. 10.1822. ≡ Satyrium latifolium Thouars, Hist. Orchid.: premier tableau des espèces d'orchidées 1re section Satyrions. tab. 10.1822 [nom. illeg., non S. latifolium L., 1759]. ≡ Habenaria chlorantha Spreng., Syst. Veg., Ed. 16, 3: 691. 1826 [nom. nov., nom. illeg. superfl., non H. latifolia Kunth, 1816]. ≡ Benthamia latifolia A. Rich. in Mém. Soc. Hist. Nat. Paris 4: 38. 1828 [nom. illeg. superfl.]. ≡ Herminium latifolium Lindl in Edwards's Bot. Reg. 18: sub tab. 1499. 1832 [nom. illeg. superfl.]. ≡ Peristylus latifolius Lindl., Gen. Sp. Orchid. Pl.: 297. 1835 [nom. illeg. superfl.]. ≡ Habenaria latifolia T. Durand & Schinz, Consp. Fl. Afric. 5: 80. 1894 [nom. illeg. superfl.]. ≡ Habenaria latifolia Cordem., Fl. Réunion (E.J. de Cordemoy): 260. 1895 [nom. illeg.]. ≡ Benthamia chlorantha Garay & G.A. Romero in Harvard Pap. Bot. 3: 53. 1998 [nom. illeg. superfl.].
Lectotypus (designated by Garay & Romero, 1998: 53): Réunion: “a la grande montée de la plaine”, s.d., Thouars s.n. (2-part specimen: P [P00094522, P00094523] images!) (Fig. 1, 2).
Notes. – In his Premier tableau des espèces d'orchidées, on an unpaginated, diagnostic table published at the front of “Histoire”, Du Petit-Thouars (1822) spelled the epithet as latosatis, whereas on plate 10, which illustrates the species, he spelled it as latisatis. In view of the fact that he often used part of the Linnean epithet (in this case latifolia) as part of his Thouarsian epithet, latosatis should be considered an orthographic variant. Furthermore, ICN commends to use an “i” as the connecting vowel. Thus, the correct epithet ought to be latisatis (ICN Art. 60.10).
The generic name Satorkis Thouars, as published by Du Petit-Thouars (1809), with that original and thus correct spelling (ICN Art. 60.1), is illegitimate since it is a superfluous name for Satyrium L. However, the epithet latisatis published under the orthographic variant Satorchis Thouars (Du Petit-Thouars, 1822) is legitimate and can be used in a new combination (ICN Art. 55.1).
When Garay & Romero (1998: 53) established Benthamia chlorantha, they cited the basionym as: “Habenaria Chlorantha Spreng., Syst. Veg. 3: 691. 1826, based on Satyrium latifolium Thouars, Hist. Orch., Prem. Tabl., t. 10, 1822, non Linnaeus 1759” and a Thouars specimen at P as the holotype. Since Satyrium latifolium is an alternative name for Satorkis latisatis Thouars, and therefore homotypic, its nomenclatural action can be accepted as an indirect typification of the latter name. However, an illustration was published as part of the protologue and should also be considered as original material. Therefore, Garay and Romero's use of holotype is an error to be corrected to lectotype (ICN Art. 9.10). It should be also noted that besides the specimen P00094522 (Fig. 1), a second sheet with a dissected flower is kept at P [P00094523]. Henri Perrier de la Bâthie studied this material for his treatment of the genus for the Flore de Madagascar et des Comores, and explicitly indicated: “A joindre au type de Thouars [to be attached to the Thouars type]” (Fig. 2). The fragment was ultimately mounted on a separate sheet at P but is clearly part of the type specimen. Therefore, it is regarded here as a 2-part specimen.
Acknowledgements
The author would like to thank Ib Friis, Finn Rasmussen, Joel Calvo, Martin Callmander, and Hugh Glen for their comments, which greatly improved the manuscript.
Published by the Conservatoire et Jardin botaniques de Genève Open access article under Creative Commons Attribution Licence (CC BY 4.0)
