Kalanchoe, Adanson, 1763

Smith, Gideon F., Shtein, Ronen & Klein, David-Paul, 2021, Kalanchoe subg. Alatae (Crassulaceae subfam. Kalanchooideae), a new rank for K. sect. Alatae, Phytotaxa 509 (2), pp. 255-258 : 255

Kalanchoe [subg. Bryophyllum ] sect. Alatae elevated to the rank of subgenus

Throughout Raymond-Hamet’s long involvement in the taxonomy of Kalanchoe in the 20 th century ( Smith 2020b), K. sect. Alatae was the only infrageneric “groupe” for which he published a name (Raymond-Hamet 1933). All the other units he recognised were furnished with numbers only, a classification he adhered to even when producing one of the first illustrated works (Raymond-Hamet & Marnier-Lapostolle 1964: 93) on a part of the genus some 60 years after having started his work on Kalanchoe in the early 1900s ( Hamet 1906, 1907, 1908).

In the case of two species that are endemic to Madagascar, namely K. porphyrocalyx ( Baker 1883: 142) Baillon (1885: 469) ( Fig. 1 ) and K. uniflora ( Stapf 1908: 258) Hamet (1910: 52) ( Fig. 2 ), Raymond-Hamet (1933) argued that they are closely related, a view with which we agree, and included them in K. sect. Alatae. Raymond-Hamet (1933: 547–548) described K. sect. Alatae as including “Plants glabrous or basally covered with simple hairs, with leaves subentire or more or less crenulate. Calyx with segments longer than the [calyx] tube. Corolla with segments shorter than the [corolla] tube, more or less ovate. Stamens inserted below the middle of the corolla tube. Carpels connate, attenuate into styles a little longer or a little shorter than the carpels. Scales sublinear or elongated-oval-sublinear. Seeds winged.” (translated from the original French in Raymond-Hamet 1933: 547–548).

Some 15 years later, Boiteau & Mannoni (1948, 1949) included K. porphyrocalyx and K. uniflora in their K. subsect. Epidendrae Boiteau & Mannoni (1948: 57), i.e., at the rank of subsection.

Gehrig et al. (2001) indicated that the two related species dealt with here, K. porphyrocalyx and K. uniflora , form a single clade.

The winged seeds of members of this subgenus have yet to be recorded in other representatives of Kalanchoe , and likely play a role in the dispersal and subsequent successful germination and establishment in suitable niches where these taxa occur, predominantly as epiphytes, in their natural habitat in Madagascar.

Figures

FIGURE 1. Kalanchoe porphyrocalyx. A. K. porphyrocalyx var. porphyrocalyx growing epiphytically in habitat in the Andringitra Massif, southern Madagascar. B. K. porphyrocalyx var. sambiranensis in cultivation in South Africa. C. K. porphyrocalyx var. porphyrocalyx growing epiphytically in habitat in Andasihisatra, east of Anjozorobe, central Madagascar. D–E. K. porphyrocalyx var. porphyrocalyx in cultivation in Madagascar, with a close up (E) of the sparsely hairy flowers. Photographs: A. Joël Jacq; B. Gideon F. Smith; C. Nadia Raheliarisoa; D–E. David-Paul Klein.

FIGURE 2. Kalanchoe uniflora. A–D. K. uniflora growing epiphytically in habitat in Parc National de Montagne d’Ambre at 1000 m above sea level, northern Madagascar. E. The winged seeds, sparsely hairy pedicel, calyx, and attenuated carpels of K. uniflora. F. Plant in cultivation in South Africa. Photographs: A–D. David-Paul Klein; E. Ronen Shtein; F. Gideon F. Smith.