Kalanchoe peltigera (Descoings, 2005)

Shtein, Ronen & Smith, Gideon F., 2021, Taxonomy and nomenclature of the southern Malagasy Kalanchoe peltigera, with reference to K. rosei var. seyrigii (Crassulaceae subfam. Kalanchooideae), Phytotaxa 490 (1), pp. 47-59 : 54-55

1. Kalanchoe peltigera and K. rosei var. seyrigii

We conclude that there are no material differences between the specimen, Seyrig 819, which was cited in the protologue of K. rosei var. seyrigii ( Boiteau & Mannoni 1949: 71) and material from which the type of the name K. peltigera was prepared. The Seyrig 819 specimen also closely coincides with the description included in the protologue of the name K. peltigera ( Descoings 2005a: 6) .

Although some traits cannot be observed in Seyrig 819, these concern only colour and measurements of the internal floral structures, the latter at any rate being limited by the overall flower size, which has been shown to be a match between the taxa. The original description provided for K. rosei var. seyrigii by Boiteau & Mannoni (1949) based on their citation of Seyrig 819 confirms that the measurements of the androecium and gynoecium and other internal floral morphological structures, too, coincide with those applicable to K. peltigera . Additional support is provided by the close geographical proximity (about 50 km) of the localities from which Seyrig 819 and the material from which the type of the name K. peltigera was prepared, originated. Seyrig 819 is therefore coextensive with material described as K. peltigera . This specimen represents the earliest documented occurrence of the species and the earliest available herbarium sheet.

Kalanchoe peltigera is a unique species and we agree with Descoings (2005a) that it represents a combination of characters that warrant recognition.

In the horticultural industry the name K. rosei var. seyrigii is often used to refer to a range of taxa that historically have been associated with K. rosei . In such instances, this name is most often correctly associated with K. rosei subsp. serratifolia , as the names are based on the same type, H. Humbert 5979 (see above), but also often confused with K. rosei subsp. variifolia . Note though that the combination ‘ K. rosei subsp. serratifolia var. seyrigii ’, which is also sometimes encountered has not been validly published, and that Boiteau & Mannoni (1949: 71) originally described it under K. rosei subsp. rosei as K. rosei subsp. rosei var. seyrigii (as ‘ Seyrigi ’).

In his compilation of Kalanchoe cultivars, Shaw (2008: 73) refers to [K.] ‘Seyrigii’ under “Sp. 30”, i.e., K. rosei , and cites “[K.] rosei var. seyrigii ” as the “Syn. / Group”, with “ Rauh (1998: 323) ” and “GW”, the website of Glasshouse Works, Church Street, PO Box 97, Stewart, Ohio 45778-0097, USA (www.glasshouseworks.com) given as references for K. ‘Seyrigii’. Under Brickell et al. (2016: Art. 21.5), the name K. rosei var. seyrigii , when treated as a cultivar, is to be written K. rosei ‘Seyrigii’. Kalanchoe peltigera as here circumscribed includes Seyrig 819, but not other material previously attributed to K. rosei var. seyrigii such as that imaged at http://www.glasshouseworks.com/ kalanchoe-rosei-seyrigi?search= Kalanchoe under “ Kalanchoe rosei seyrigi [spelled with one ‘i’ after the ‘g’]”.

Rauh (1998: 323) gave the following description for K. rosei var. seyrigii , which he ascribed to “Mann. & Boit.”, i.e., Boiteau & Mannoni, but in the opposite sequence: “Leaves lanceolate, 4–5 cm long, 5–6 mm wide, margins dentate-serrate. This variety occurs between Bekily and Tsivory”. These traits describe K. rosei var. seyrigii based on its type material [“ Toliara, 4–5 km north of Fort-Dauphin, towards the lagoon, max. 25 m asl, 20 September–6 October 1928, H. Humbert 5979 ”] which is from the Tolagnaro region instead. Only K. peltigera , including the specimen Seyrig 819, occurs between Bekily and Tsivory (as discussed in ‘Results’, see Fig. 4 ).

At any rate, as discussed below under “Taxonomic affinities of Kalanchoe peltigera ”, K. peltigera is not particularly closely related to either K. rosei var. variifolia or to K. rosei var. seyrigii , the correct name of K. rosei subsp. serratifolia at the rank of variety.

Figures

FIGURE 4. Occurrences of specimens historically associated with K. rosei. © OpenStreetMap contributors.