Begonia sect. Knesebeckia (Klotzsch) A.DC.

Moonlight, Peter. W., Jara-Muñoz, Orlando A., Purvis, David A., Delves, Jay, Allen, Josh P. & Reynel, Carlos, 2023, The genus Begonia (Begoniaceae) in Peru, European Journal of Taxonomy 881, pp. 1-334 : 192

Begonia sect. Knesebeckia (Klotzsch) A.DC.

Annales des Sciences Naturelles Botanique, Série 4 11: 125 ( de Candolle 1859). – Knesebeckia Klotzsch, Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königl. Preuss. Akademie der Wissenschaften zu Berlin 1854: 122 ( Klotzsch 1854).

– Type: lectotype: Knesebeckia incarnata (Link & Otto) Klotzsch ≡ Begonia incarnata Klotzsch , designated by Barkley & Baranov (1972: 4).

Synonymy notes

For a full list of sectional synonyms, see Moonlight et al. (2018).

Notes

The current circumscription of Begonia sect. Knesebeckia is a “taxonomic dustbin” composed of mostly Central American and Andean caulescent species with four tepals on the staminate flower, five tepals on the pistillate flower, and divided placentae. Moonlight et al. (2018) demonstrated that the section is polyphyletic with at least four clades, a central American clade including the type species and three Andean clades. Peruvian species fall into all three Andean clades, and we recognise one of these as Begonia sect. Apteron above. The two other clades are found in Peru but, as no morphological characters have yet been found to identify these clades, we do not recognise them formally herein. Rather, we group species into two informal groups, the acerifolia and the maynensis groups. While perhaps not monophyletic, these groups are easily recognisable and of use for identifying species.

The current circumscription of Begonia sect. Knesebeckia includes fifteen species in Peru, of which seven are in the acerifolia group and four are in the maynensis group. We describe one new species, provide the first record of a second, and provide one new synonym within this section. Five species are endemic to Peru.