Kalanchoe ceratophylla Haworth (1821: 23)

Smith, Gideon F., 2025, Revisiting the nomenclature and taxonomy associated with the name Kalanchoe ceratophylla (Crassulaceae subfam. Cotyledonoideae), Phytotaxa 698 (4), pp. 285-293 : 287-289

Kalanchoe ceratophylla Haworth (1821: 23) .

Homotypic synonym:— Vereia ceratophylla (Haw.) Dietrich (1840: 1328) .

Type:—Partly coloured painting of Kalanchoe ceratophylla executed [“del.”] by Thomas Duncanson, Library and Archives section, Royal Botanic Gardens, Kew. The plate is undated. In the lower right corner next to the painting, on the backing board, “60.01/3 A-C” is written in pencil. Here designated as neotype ( Fig. 1 ).

[The statement of Wickens (1982: 673): “Plant cultivated at Kew ex China (holotype not traced; represented by a drawing by T. Duncanson c. 1822–26, K!)” was not an effective typification and cannot be corrected under Turland et al. (2018: Art. 9.10); further discussed below].

Heterotypic synonyms:— Kalanchoe teretifolia Haworth (1831: 53 , t. 166) in Wallich (1831), not K. teretifolia of Deflers (1894: 299). Type:—Coloured plate of Kalanchoe teretifolia Haw. published in Wallich (1831) as “Tab. 166” after p. 54, here designated as lectotype.

Cotyledon serrata Blanco (1837: 382) , non C. serrata Linnaeus (1753: 429) . Type:—not typified. [Manuel María Blanco Ramos (1778– 1845) did not leave a herbarium ( Smith 2023a, 2023b).]

Cotyledon lanceolata Blanco (1837: 382) , non C. lanceolata Forsskål (1775: 89) . Type:—not typified. [Manuel María Blanco Ramos (1778–1845) did not leave a herbarium ( Smith 2023a, 2023b).]

Bryophyllum serratum (Blanco) Blanco (1845: 220) , not of Lauzac-Marchal (1974: 2508). Type:—not typified. [Manuel María Blanco Ramos (1778–1845) did not leave a herbarium ( Smith 2023a, 2023b).]

Kalanchoe macrosepala Hance (1870: 5) . Type:— Hong Kong, April 1858, H.F. Hance 1723 [the only specimen cited, with no evidence traced that more than a single specimen was prepared under this number of Hance] (holotype, Herb. BM).

Kalanchoe gracilis Hance (1870: 6) . Type:—Formosa [ Taiwan], 1861, H.F. Hance [R. Swinhoe?] 7578 [the only specimen cited, with no evidence traced that more than a single specimen was prepared under this number of Hance / Swinhoe] (holotype, Herb. BM).

Kalanchoe takeoi Hayata (1919: 33) . Type:—NAnTō, HokusAnkō, SepTemBer 1916, T. Itō s.n. [the only specimen cited] (holotype, fide Wickens (1982: 673), Herb. TI).

Nomenclatural notes on the name Kalanchoe ceratophylla :— Wickens (1982:674) recorded that Kalanchoe ceratophylla was “introduced [to the Royal Botanic Gardens, Kew,] from China in 1820 by Captain Nisbett”. One year after this introduction, when Haworth (1821: 23) published the name K. ceratophylla , he did not cite any material. One page further on, he only stated that: “Viget in regio horto Kewense”. [English: “It thrives in the garden at Kew.”], so indicating that he published the name based on living material cultivated at the Royal Botanic Gardens, Kew. Haworth (1821: 24) further added that: “Fortasse Bryophylli species, nempe folia facillimè radicant. Flores docebunt.” [English: “Perhaps [it is] a species of Bryophyllum , because the leaves root very easily. This [its genus placement] will be determined from the flowers.”]. However, at the time that he described the species, he had yet to see the flowers [“ Flores ignoti.” / “Flowers unknown.”]

Even eight years later, when Haworth (1829: 320) treated K. ceratophylla in his 10-species monograph, it was still not entirely clear that he had in fact seen the flowers of this species, because he stated: “ Floret in Hort. Kew, Nov.–Jan. sed flavos flores non vidi. [...] Obs. Minùs erectus quàm in sequentibus.” [English: “Flowers in Hort. Kew, Nov.–Jan. but I saw no yellow flowers. [...] Observation. Less erect [probably the plant?] than in the following [species, i.e., K. laciniata ]”.

Wickens (1982: 674) stated, for the name K. ceratophylla , that the: “Type: [Is a P-]plant cultivated at Kew ex China (holotype not traced; represented by a drawing by T. Duncanson c. 1822–26, K!).” However, the type of a name cannot be a living plant and, furthermore, the name K. ceratophylla cannot have a holotype because, as indicated in the first paragraph under the heading ‘ Nomenclatural notes:—’, above, Haworth (1821: 23–24) did not cite any material in the protologue of the name.

Regarding the existence of possible material of K. ceratophylla , even if not cited, that Haworth might have kept in his herbarium, which consisted of about 20,000 specimens ( Stearn 1965: 25), it has been recorded that his herbarium was acquired by Harry B. Fielding (1805–1851) who bequeathed it to the University of Oxford. Fielding used Haworth’s herbarium as study material and, evidently not realising its importance, threw away most of the specimens “[...] as he acquired smarter ones” ( Stearn 1965: 25, Bayer et al. 1999: 7). Fielding’s herbarium is now at Oxford (Herb. OXF). No specimens of K. ceratophylla that Haworth might have prepared are extant at Herb. OXF (S.K. Marner, pers. comm. by email on 12 November 2024).

Kew holds an illustration of K. ceratophylla executed [“del.”] by Thomas Duncanson in their Library and Archives section (E. Harry, pers. comm. by email on 1 August 2024). The plate is undated and in the lower right next to the painting, on the backing board, “60.01/3 A-C” is written in pencil. The name written at the bottom of the painting reads: “ Kalanchoe ceratophylla Haw ”, with “Haw” underlined. The plate is of partly coloured fertile material—an inflorescence branch and some bracts, and some floral dissections—with most of the rest of the material only faintly illustrated in outline in black ink or in pencil.

Since this plate shows material in flower and Haworth (1821) unambiguously stated that he had not seen the flowers at the time that he published the name, the plate cannot be interpreted as original material in the sense of Turland et al. (2018: Art. 9.4). The name K. ceratophylla is therefore here neotypified on the plate held at the Royal Botanic Gardens, Kew.

Ohba (2002: 254) did not cite the type of the name K. ceratophylla .

Incidentally, the name K. rotundifolia ( Haworth 1824: 188) Haworth (1825: 31) , which is applied to South African material was also neotypified on a RBG Kew-held plate, which is dated “Octob.[-er] 1 st. 1823”, prepared by Thomas Duncanson ( Figueiredo & Smith 2017: 108, 111).

Nomenclatural notes on the name Kalanchoe teretifolia :— Wickens (1982: 673) stated that the type of the name K. teretifolia is: “ Burma, Taong Dong near [20 miles / 32 km from] Ava, Wallich 7223 (holotype K!).” However, no specimens or gatherings were cited in the protologue of the name K. teretifolia [see Haworth in Wallich (1831: 53)], and reference to the location only from where material was obtained (see above) does not qualify as mention of a single specimen or gathering ( Turland et al. 2018: Note 2 under Art. 40.3). Under Turland et al. (2018: Art. 9.4) the plate of K. teretifolia published in Wallich (1831: t. 166) qualifies as original material and this plate is here designated as lectotype of the name K. teretifolia .

Nomenclatural note on the name Bryophyllum triangulare :—The name Bryophyllum triangulare Blanco (1845: 221) was included in the synonymy of the name K. ceratophylla by Wickens (1982: 673). However, Smith (2023a: 435–436) showed that the name B. triangulare was the first name published for the Malagasy species today known as K. tomentosa Baker (1882: 110) . Since the name B. triangulare , which applies to material at present known as K. tomentosa , predates the latter by 37 years, under Turland et al. (2018: Art. 11.4), the epithet ‘ triangulare ’, correctly declined, should have been adopted by Baker (1882: 110) when he included the species in Kalanchoe . In the interest of nomenclatural stability, the name B. triangulare was therefore proposed for rejection ( Smith 2023a: 435–436) because the name K. tomentosa is well-established in the taxonomy and horticulture of Kalanchoe ( Smith 2023b: 292, 295). This proposal was supported by the Nomenclature Committee for Vascular Plants ( Applequist 2024: 302), the General Committee ( Wilson 2024: 1083), and at the Plenary Session of the XXth International Botanical Congress held on 27 July 2024 in Madrid, Spain. This name is therefore to be cited as “ Nom . utique rej.:— Bryophyllum triangulare Blanco (1845: 221) ” and, at any rate, does not belong in the synonymy of K. ceratophylla .

Figures

FIGURE 1. Image of the partly coloured painting of Kalanchoe ceratophylla executed [“del.”] by Thomas Duncanson, held in the Library and Archives section, Royal Botanic Gardens, Kew. The plate is undated. In the lower right corner next to the painting, on the backing board, “60.01/3 A-C” is written in pencil. This plate is here designated as neotype of the name K. ceratophylla. The plate is copyright and reproduced with the kind permission of the Director and the Board of Trustees, Royal Botanic Gardens, Kew.