Taxonomy of the Begonia Tiliifolia Group, Including Descriptions of Two New Species

Abstract

Begonia albomaculata as circumscribed in the Flora of Ecuador and related publications is shown to be a misapplied name and represents an undescribed species. This is described as Begonia botryoides Moonlight & Tebbitt sp. nov., and is recorded from the Pichincha, Santo Domingo de los Tsáchilas, Napo, Cotopaxi, Azuay and El Oro provinces in Ecuador, and the Antioquia and Chocó departments of Colombia. The taxonomic study of this species prompted a re-evaluation of related species. It was subsequently found that the Central American material previously included in Begonia tiliifolia C.DC. is distinct from the type and other South American material of this species and represents an undescribed species. This is described as Begonia boreoharlingii Tebbitt & Moonlight sp. nov., and is recorded from the Limón province in Costa Rica, and the Bocas del Toro and Coclé provinces in Panama. Four species, Begonia tiliifolia C.DC., Begonia harlingii L.B.Sm. & Wassh., B. botryoides and B. boreoharlingii, are placed in the informally named Begonia tiliifolia group. A key, descriptions, illustrations and distribution maps are provided for the members of the Begonia tiliifolia group, and its sectional classification is discussed.

A New Species of Begonia From the Chocó Biogeographical Region of Colombia

“…Ruizopavonia could not be clarified in the present study, because only a few species from this section were sampled. Although morphological data suggest an affinity between Begonia embera and the B. tiliifolia group, as defined by Tebbitt et al (2017), our ITS phylogeny seems to contradict this (see Figure 1). In the topology presented by Moonlight et al (2018), based on three chloroplast markers, Begonia botryoides is placed as sister to B. tiliifolia, and then sister to two species outside the B. tiliifolia group: B. seemanniana A.DC.…”

“…These observations provide insights into the habitat requirements of the species, which is probably restricted to narrow basins under dense canopy. In light of the considerations above, according to IUCN criteria (IUCN (Tebbitt et al, 2017). This group is characterised by its five female tepals, vs fewer than five in the other species of Begonia sect.…”

Resolving Phylogenetic and Taxonomic Conflict in Begonia

“…Clade names can be used informally above and below the section Informal names have been used successfully in Begonia below the rank of section (e.g. the 'tiliifolia' group (Tebbitt et al, 2017) and the 'calcarea' group (Kiew et al, 2016) and for larger groups above section (e.g. the Diploclinium grade, the Wagenaria clade and Malagasy Begonia (MB) (Moonlight et al, 2018).…”

A New Species of Begonia Sect. Ruizopavonia From Colombia and Ecuador

“…In Ecuador and southern Colombia, all members of Begonia sect. Ruizopavonia are found on the eastern slopes of the Andes, except those of the 'tiliifolia group' (see Tebbitt et al, 2017). Members of the tiliifolia group are distinguished by the short internodes in their inflorescences, which appear umbellate; this is not the case in the new species.…”

“…Its distribution stretches from Chiapas State in southeastern Mexico to Bolivia. Species in this section are distinguished from members of other sections as large, upright, usually scandent herbs, lacking tubers or rhizomes, with more or less straight leaves with distinct pinnate (rarely palmate-pinnate) venation, and winged fruits (Doorenbos et al, 1998;Tebbitt et al, 2017;Moonlight et al, 2018). Members of the section are typically found at the edge of montane forest patches, where they scramble through dense vegetation.…”