Kalanchoe stuhlmannii Engler (1895: 188)

Smith, Gideon F., 2025, A review and analysis of names and designations published for species and varieties of Kalanchoe (Crassulaceae subfam. Cotyledonoideae) by Adolf Engler (1844 - 1930) between 1892 and 1913, Phytotaxa 682 (1), pp. 1-28 : 11-12

3. Kalanchoe stuhlmannii Engler (1895: 188) .

Type:—EAST AFRICA [TROP. OST-AFRIKA]. Tanzania, [Bukoba District], Karagwe, Kitangula [Kitangola], “Auf Tonboden in Umzäunungen der Felder”, 1170 m, 16 February 1891, F.L. Stuhlmann 1643 (holotype, treated as “Type” by Raadts (1977: 152), Herb. B barcode B 10 0241956! [Image of the specimen available for examination online at http://herbarium.bgbm.org/object/B100241956]), here corrected to holotype.

Isotype:—EAST AFRICA [[TROP.] OST-AFRIKA]. Tanzania, [Bukoba District], Karagwe, Kitangula [Kitangola], [16 February 1891], F.L. Stuhlmann 1643 (isotype, Herb. P barcode P03244931 [Image of the specimen available for examination online at http://coldb.mnhn.fr/catalognumber/mnhn/p/p03244931]).

Nomenclatural notes:—When Engler (1895: 188) published the name K. stuhlmannii , the only material that he cited was “Stuhlm. n. 1643”, from “Karagwe, Kitangula”. The specimen is held at Herb. B and has the barcode B 10 0241956. In the case of the name K. stuhlmannii, Raadts (1977: 152) did not express a view on the sort of type that the specimen F.L. Stuhlmann 1643 could be. Taxonomically, Raadts (1977: 151) treated K. stuhlmannii as a “Species incertae” (further discussed under “ Taxonomic notes:—”, below). As far as is known no other material of F.L. Stuhlmann 1643, apart from the isotype (see next paragraph), is in existence.

The isotype of the name K. stuhlmannii held at Herb. P, with barcode P03244931, consists of a small, folded paper capsule only, which is attached to a standard herbarium mounting board. The capsule presumably contains plant fragments only.

Taxonomic notes:— Kalanchoe stuhlmannii was treated as a “Species incertae” by Raadts (1977: 151–152); Wickens (1987: 58), who followed the treatment of Raadts, similarly regarded it as an “Imperfectly known species”; and Descoings (2003: 144) treated the name as being of “unresolved application”.

Alternatively it has been suggested that K. stuhlmannii belongs in the synonymy of K. marmorata Baker (1892: 300) var. marmorata . However, Smith (2021: 97–98, 2022b: 105–107) did not follow the latter view, rather concurring with Raadts (1977: 151–152), Wickens (1987: 58), and Descoings (2003: 144) that, based on the material at hand, which lacks vegetative parts, a conclusive identification remains elusive. Although the flowers of K. marmorata var. marmorata vary in length ( Smith 2022b: 108), they are often very long—up to 125 mm —while the preserved flowers comprising F.L. Stuhlmann 1643 are considerably shorter.

Biographical notes:— Verdcourt (1988, 1989a, b, 2024) and Polhill & Polhill (2015: 444–447) provide comprehensive biographical treatments of Franz Ludwig Stuhlmann (Hamburg, Germany, 29 October 1863 – 19 November 1928, Hamburg, Germany), including of his itineraries and collecting activities in East Africa.