Euphorbia candelabrum Trémaux ex Kotschy, 1857

Figueiredo, Estrela & Smith, Gideon F., 2020, Typification of Euphorbia candelabrum (Euphorbiaceae) and associated names, Phytotaxa 447 (3), pp. 216-220 : 217-218

Typification of Euphorbia candelabrum Trémaux ex Kotschy

The name currently cited in the literature as E. candelabrum Trémaux ex Kotschy was published by Kotschy (1857) as ‘ Euphorbia candelabrum Tremeau’ without further reference to either literature or material. Five years later, Boissier (1862: 84) was apparently the first to assume that ‘Tremeau’ was a misspelling of ‘Trémaux’. Thus, Boissier (1862) cited the name as E. candelabrum Trémaux ex Kotschy [Klotzsch, sic] and placed ‘ E. canariensis Trémaux , voy. pitt. Soudan t. XIV.’ in its synonymy. However, nowhere did Kotschy (1857) refer to any of Trémaux’s publications nor to ‘ E. canariensis Trémaux’. Furthermore, the epithet ‘ candelabrum ’ that Kotschy (1857) ascribed to ‘Tremeau’ is not mentioned in Trémaux’s work that contains Plate 14 cited by Boissier (1862), i.e., the Atlas ([…] atlas de vues pittoresques […]) (Trémaux 1852–1859). As argued by Leach (1981), making a connection between the name E. candelabrum and Trémaux’s plate of E. canariensis is, at best, extremely tenuous, and rooted in an assumption that there was communication between the authors, of which no evidence exists. Carter (1985) argued that, since Trémaux’s Plate 14 has the title ‘Plantes venenifiques’ [in fact a subtitle below the plate] and Kotschy (1857) used the epithet ‘venefica’ in the name ‘ Euphorbia venefica Tremeau’, there is an indirect link between the two authors.

Boissier (1862: 84) mentioned a single plate under E. candelabrum , i.e., Plate 14. This cannot be considered an effective typification since he did not mention the word type or equivalent ( Turland et al. 2018: Art. 7.11). Brown (1912: 599), under ‘186. E. candelabrum Trémaux ex Kotschy’, cited two plates as part of his references to the earlier works of Boissier (1862) and Trémaux (1852–1859), as follows: ‘Boiss. in DC. Prodr. xv. ii. 84. E. canariensis, Trémaux, Voy. Soudan Orient. Atlas, tt. 13–14, with description.’; this citation of two plates was followed by subsequent authors such as Carter (1985 & 1988).

Leach (1981) questioned the publication date of Trémaux’s plates, noting that it was not clear that they antedated Kotschy’s publication. Trémaux’s Atlas consists of 61 plates that were issued in parts (livraisons) at different times, starting in 1852. Carter (1985), who cited the publication as ‘Trémaux, M. [sic] 1853. Voyages au Soudan Oriental, Atlas: tabs. 13, 14 with text. Borrani, Paris’, considered the date of publication of Plates 13 and 14 to be 1853, ‘according to the copy deposited in the library of the Royal Geographical Society, London’ ( Carter 1985: 700). Trémaux’s Atlas is presently cited in catalogues (e.g. of the Bibliotèque Nationale de France) as dating from 1852 to 1859. The Atlas does not contain information on the dates of each livraison.

Plates 13 and 14 of the Atlas were cited as types of E. candelabrum Trémaux ex Kotschy by Carter (1988: 485) [‘Trémaux, Voy. Soudan Orient., Atlas: pl. 13 & 14 (1853)’], but this was not an effective typification of the name as under Turland et al. (2018: Art. 8.1) a lectotype is ‘[…] a published illustration […]’ [note singular].

Both plates 13 and 14 depict more than one species. Plate 13 depicts several distinct plants, representing at least three taxa: two trees that dominate the landscape, as well as a shrub in the right foreground.

Bruyns & Berry (2019) designated Plate 13 as lectotype. They mentioned ‘… Euphorbia canariensis …’ in their typification, but did not clearly indicate in that type designation, as they did in the caption to their Figure 5 on p. 834, that the lectotype refers only to the large illustration of a candelabra-shaped tree on the right of the plate. Furthermore, they did not indicate in the designation, nor in the caption to Figure 5, which of the two plants on the right, i.e. the tree or the shrub, they referred to. This has resulted in ambiguity and their proposed lectotypification not being effective under Turland et al. (2018: Art. 9.11).

The name E. candelabrum Trémaux ex Kotschy is here unambiguously lectotypified with the illustration on the extreme right of Plate 14 in Trémaux (1852–1859; Pl. 14 dating from 1853 fide Carter 1985). Below the illustration on the extreme right is printed ‘ Euphorbia canariensis’. This is the plate that was first associated with the name E. candelabrum Trémaux ex Kotschy , by Boissier (1862: 84).

No material of E. candelabrum that was collected by Kotschy is currently known to exist at Herb. W, where Kotschy was employed in the forerunner of the Naturhistorisches Museum Wien (C. Bräuchler, pers. comm). A considerable number of the reportedly 300,000 specimens collected by Kotschy is kept at W.

Euphorbia candelabrum Trémaux ex Kotschy (1857: 169) , nom. illeg., non Welwitsch 1855 or 1856 [assuming the PNC for Vascular Plants, GC, and future IBC will rule that Euphorbia candelabrum Welwitsch was validly published in either 1855 or in 1856].

Lectotype (designated here):— [illustration] Branch on the extreme right side of Plate 14, with the caption ‘ Euphorbia canariensis’ below it, in Trémaux , Voy. Soudan Oriental et dans l’Afrique Septentrionale, Atlas. 1852–1859; Pl. 14 dating from 1853 fide Carter (1985).