Begonia sect. Donaldia (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 : 115-116

Begonia sect. Donaldia (Klotzsch) A.DC.

Annales des Sciences Naturelles Botanique, Série 4 11: 127 ( de Candolle 1859). – Donaldia Klotzsch, Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königl. Preuss. Akademie der Wissenschaften zu Berlin 1854: 127 ( Klotzsch 1854).

– Type: lectotype: Donaldia ulmifolia (Willd.) Klotzsch ≡ Begonia ulmifolia Willd. , designated by Swart, Index Nominum Genericorum Card 09630).

Notes

Begonia sect. Donaldia is, in many respects, similar to B. sect. Ruizopavonia. The two sections both have pinnate venation, two tepals on the staminate flower, and winged ovaries and fruits. In Peru, the two sections can be distinguished by the number of tepals in the pistillate flower: five in B. sect. Donaldia and two in B. sect. Ruizopavonia, but B. nunezii Moonlight sp. nov. and Bolivian members of the latter section can also have five tepals. When sterile, the two sections can be distinguished in Peru by their indumentum. The lower leaf lamina of B. ulmifolia is densely tomentose but the lower leaf laminae of all Peruvian species of B. sect. Ruizopavonia are glabrous, though they can have an indumentum on the veins on the underside of the leaves.

The number of species in Begonia sect. Donaldia was increased from two to three by the inclusion of B. gesnerioides L.B.Sm. & B.G.Schub. by Moonlight et al. (2018). We reduce the number of species to two once more, by treating this species as a synonym of B. ulmifolia . This change was discussed but not in formalised Moonlight et al. (2018).