(3049) Proposal to reject the name Camphorosma glabra (Camphorata glabra) (Chenopodiaceae)

(3049) Camphorosma glabra L., Sp. Pl.: 122. 1 Mai 1753 [Angiosp.: Chenopod. / Amaranth.], nom. utique rej. prop. Typus: non designatus. In continuing our efforts to clarify the Linnean species of Camphorosma (Freitag & Iamonico in Phytotaxa 202: 235–236. 2015; Iamonico & Freitag in Taxon 64: 816–821. 2015, 73: 313–314. 2024; Iamonico & al. in Taxon 72: 929–930. 2023) here we propose the rejection of Camphorosma glabra L. Linnaeus (Sp. Pl.: 122. 1753) published Camphorosma glabra by providing a short diagnosis ("CAMPHOROSMA foliis semitriquetris glabris inermibus"), the provenance ("Habitat in Helvetia"), and the symbol for perennial life form ("♃"), with these data taken from his Amoenitates academicae (Linnaeus, Amoen. Acad. 1: 393. 1749). Two synonyms were cited: "Camphorata foliis confertissimis inermibus laevibus" from Haller (Enum. Meth. Stirp. Helv. 1: 183. 1742, not "193" as originally reported) and "Camphorata glabra" from Bauhin (Pinax: 486. 1623, not "286") and Daléchamps (Hist. General. Pl.: 1179. 1586). The latter refers to an illustration of a "Camphorata minor" (https://bibdigital.rjb.csic.es/viewer/13561/?offset=#page=85), not "Camphorata glabra" as reported by Linnaeus (l.c. 1753). This illustration may be considered part of the original material for Camphorosma glabra, but the different name cited by Linnaeus (l.c. 1753) makes this doubtful. In searching for original material, we traced two specimens seen by Linnaeus, one of unknown provenance at LINN (no. 165.4, image at https://linnean-online.org/307/) and the other in the Burser Herbarium at UPS (No. XXV.56). LINN-165.4 bears one sterile branch of a perennial plant and the Linnaean annotations "Polycnemum" and "glabra". Lacking the relevant Species plantarum number ("3" in the case of C. glabra), this specimen at LINN must be considered as a post-1753 addition to the collection and not as original material (see Jarvis, Order out of Chaos: 41–44. 2007). Furthermore, the morphology of LINN-165.4 is in contrast with the protologue: the filiform leaves are rather densely pilose (not glabrous). LINN-165.4 matches the current concept of C. monspeliaca (see, e.g., Ball in Tutin & al., Fl. Eur., ed. 2, 1: 98. 1993; Iamonico in Pignatti & al., Fl. Ital., ed. 2, 2: 57–58. 2017). The UPS specimen bears two flowering branches of a perennial plant (most likely parts of the same plant), a label with "Camphorata glabra Bauh., Nisi sit eadem cum subsequente" (If not identical with the subsequent one – that is Camphorata congen.) and "In Vallesia" (Upper Rhône valley, Switzerland), as well as the Linnaean script "Camphorosma". The locality seemingly matches the Linnaean provenance given in the protologue ("Habitat in Helvetia"). However, again contrary to the description, the leaves are pubescent. As the perianth is likewise pilose, bracteoles are lacking, and several flowers are aggregated in the axils of bracts, we identify the UPS specimen as Bassia prostrata (L.) A.J. Scott, as already reported by Juel (in Nova Acta Regiae Soc. Sci. Upsal., ser. 4, 5(7): 121. 1923). This identification is supported by leaf sections which show an arrangement of the Kranz cells in arch-like groups above the vascular bundles instead of forming a continuous ring below the palisades and so are of the Bassia prostrata and not the Camphorosma type (Freitag & Kadereit in Pl. Syst. Evol. 300: 665–687. 2013). It is also noteworthy that Bauhin (l.c.) based his name on a plant from a locality near Basel ("Otlingen" – cited by Haller [l.c. 1742] as "Oetlingen") which is very far from the Upper Rhône valley. Neither specimen (at LINN and UPS) is suitable for the purpose of lectotypification. The illustration in Daléchamps (l.c.) shows a multi-stemmed plant with verticillate leaves and a thick perennial taproot; flowers and fruits are missing. According to the description given by Daléchamps (l.c.), the leaves are pubescent ("folia […] a tergo modice hirsuta" [leaves slightly pubescent on the dorsal surface]). Therefore, even if considered original material, Daléchamps's illustration is in contrast with the Linnaean diagnosis and not appropriate as a lectotype. Furthermore, by the verticillate arrangement of leaves and the reference to a species of Plinius ("Chamaepeuce plinii"), the image certainly shows a Mediterranean plant which, due to the very schematic appearance of the wood cut, we are unable to identify. Lacking material that could be used as a lectotype for Camphorosma glabra, a neotypification would be required (Art. 9.6 of the Shenzhen Code; Turland & al. in Regnum Veg. 159. 2018). We checked the remaining synonyms cited by Linnaeus and related specimens: the Bauhin specimen of Camphorata glabra kept in UPS was already considered as seen by Linnaeus. A second specimen in BAS (BAS No. B05-001) was collected in E Germany and correctly identified by August Binz as Polycnemum arvense. Two more plants named Camphorosma glabra on the sheet BAS (No. H845) collected by Bauhin's pupil J. Hagenbach near Basel (the same region as given by Bauhin) likewise have an annual habit and acuminate leaves. Haller later (Hist. Stirp. Helv. 2: 263. 1768) named them Polycnemon and described the leaves as terminating in an "arista alba". Haller's herbarium book in P (114, Apetalae, Polystemones) also includes only several specimens of Polycnemum arvense but none from the type region of C. glabra. Any further attempt at choosing a specimen as neotype failed due to Linnaeus's confusing taxonomic concept of Camphorosma glabra. His diagnosis doesn't fit any of the known species of Camphorosma (see Kadereit & Freitag in Taxon 60: 51–78. 2011). Furthermore, it has to be stated that, in contrast to the provenance given by Linnaeus (l.c. 1753, "Habitat in Helvetia"), the genus Camphorosma has never been recorded from Switzerland (see, e.g., InfoFlora, https://www.infoflora.ch/it/#. 2024, accessed 10 Aug 2024). All things considered, we reached the conclusion that Linnaeus obviously mixed up characters that can be found both in Camphorosma monspeliaca and Bassia prostrata (perennial habit, non-pungent leaves) with those of Polycnemum arvense (glabrous leaves, occurrence in Switzerland). This remains somewhat surprising because in his Amoenitates (Linnaeus, l.c. 1749: 392) he very clearly outlined the differences between those genera. Camphorosma glabra is rather often cited in earlier literature but almost absent from modern treatments. Moquin-Tandon (Chenop. Monogr. Enum.: 99. 1840) cited it with a question mark as identical to his C. monspeliaca var. glabrescens and listed it (p. 100) under "Species not satis notae". He also took this view into his treatment in Candolle (Prodr. 13(2): 1126. 1849) and was followed by Beck (in Reichenbach, Icon. Fl. Germ. Helv. 24: 149. 1908). Crantz (Inst. Rei Herb.: 114. 1766) still used Bauhin's Camphorata glabra that Ascherson & Graebner (Syn. Mitteleur. Fl. 5(1): 155. 1913) recombined to Camphorosma monspeliaca L. var. glabra (Crantz) Aschers. & Graebn. and applied it to "almost glabrous forms" (the authors reported the Linnaean Camphorosma glabra with a question mark, so highlighting doubts on the synonymization). Recently, the taxon has been almost neglected, and when it is cited, as in the online databases POWO (https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:164608-1) and WFO (https://www.worldfloraonline.org/taxon/wfo-0000583026), then simply as a synonym of Camphorosma monspeliaca because in that species the degree of hairiness is rather variable and also depends upon the age of the leaves. Nevertheless, although the application of the name has somewhat stabilized as a minor variation of Camphorosma monspeliaca, the failure to properly designate a lectotype or a neotype, and the small number of citations of this name in literature, culminate here in the proposal to reject this Linnaean name. We gratefully acknowledge the support given by the curators of several herbaria in granting access to their collections (BM, LINN) to the first author and for providing scans of the respective specimens (BAS, P, UPS). We also thank Dr. Charlie Jarvis, Dr. John Wiersema and Dr. John McNeill for their assistance, advice and comments in order to improve the proposal.