Callianthe is a genus of flowering plants in the family Malvaceae (order Malvales), placed within the tribe Malveae. It comprises approximately 50 accepted species of shrubs and, rarely, small trees native to the Neotropics, with its greatest species richness centred in South America, particularly Brazil.
Plants in the genus are predominantly terrestrial shrubs. Species were historically included in the large and heterogeneous genus Abutilon and were segregated into Callianthe following molecular phylogenetic work that demonstrated the polyphyly of Abutilon as traditionally circumscribed. The genus was described by Donnell, and its treatment is reflected in Flora do Brasil 2020 (Takeuchi 2015, 2020) and the World Checklist.
In Brazil, species of Callianthe grow across a wide range of forest biomes, including the Atlantic Forest (wet rain forest and mixed Araucaria forest), Seasonal Deciduous and Semi-deciduous Forest, Gallery Forest, Cerrado, and Caatinga. The genus extends across the broader Neotropical region, reaching from Mexico and Central America through South America. Well-known species include Callianthe striata, C. amoena, C. schenckii, and C. pauciflora. The cultivar group known as 'Bouncing Bells' (sometimes still sold under the name Abutilon) represents the ornamental appeal of the genus, with pendant, bell-shaped flowers in orange, red, and yellow tones characteristic of many Malvaceae.
Distribution
Callianthe is distributed throughout the Neotropics, from Mexico and Central America south through South America. The greatest concentration of species occurs in Brazil, where members inhabit Atlantic Forest, Cerrado, Caatinga, and gallery forest biomes.
Ecology
Most species are terrestrial shrubs of tropical and subtropical forests. In Brazil they are recorded from wet Atlantic Forest (Floresta Ombrófila), mixed Araucaria forest, seasonal deciduous and gallery forests, and, less commonly, Cerrado and Caatinga scrub. At least one species (Callianthe latipetala) reaches small-tree stature.
Taxonomy Notes
Callianthe (Donnell) was segregated from Abutilon following molecular phylogenetic studies showing that Abutilon sensu lato is polyphyletic. Species previously placed in Abutilon and now referred to Callianthe retain Abutilon as a basal synonym; many cultivated plants are still sold under that name. The genus is placed in tribe Malveae, family Malvaceae, order Malvales.
