Begonia sect. Ruizopavonia 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 : 263

Begonia sect. Ruizopavonia A.DC.

Annales des Sciences Naturelles Botanique, Série 4 11: 139 ( de Candolle 1859).

– Type: holotype: Begonia alnifolia A.DC.

Notes

Begonia sect. Ruizopavonia was described by de Candolle to accommodate several Andean species with two tepals on both the staminate flower and pistillate flower, bifid placentae, and bifid styles. Its circumscription has been periodically altered since. Doorenbos et al. (1998) expanded the section to include some species with five tepals but moved all species with transversely ovate leaves to B. sect. Cyathocnemis . Moonlight et al. (2018) further refined the concept, moving species with indistinct venation to B. sect. Lepsia and favouring a distinction between palmate-pinnate venation and pinnate venation over a distinction between transversely ovate and straight leaves. Most members of this section are easily recognised as pinnately veined species with two tepals on both the staminate and pistillate flower.

Throughout the process of producing this account and a checklist of Bolivian Begonia ( Moonlight & Fuentes 2022) , it has become increasingly clear that the current circumscription of B. sect. Ruizopavonia is untenable. Doorenbos et al. (1998) included several Bolivian species in the section, which differ from the section sensu stricto in their multifid styles, dense indumentum, and palmate-pinnate venation ( B. buchtienii Irmsch. ). Several members also differ in their pistillate flower with five tepals. These species have not yet been included in any molecular phylogenies so Moonlight et al. (2018) tentatively assigned them to B. sect. Ruizopavonia. In this account, we describe B. nunezii sp. nov., which has bifid styles, but is clearly closely related to the Bolivian species by virtue of its dense indumentum, palmate-pinnate venation, and five tepals on the pistillate flower. We tentatively assign B. nunezii sp. nov. to B. sect. Ruizopavonia.

We recognise four species of B. sect. Ruizopavonia within Peru. This includes two newly described species and one new record for the country. We also recognise much increased circumscriptions of B. glauca (Klotzsch) Ruiz & Pav. ex A.DC. and B. peruviana , each including four newly proposed synonyms.