Tacinga is a small genus of cacti in the family Cactaceae (order Caryophyllales), described by Britton & Rose in 1919. All species are endemic to northeast Brazil, where they grow in the dry scrublands and thorny forests of the Caatinga biome — one of the world's most biodiverse tropical dry ecosystems, restricted to states including Bahia, Pernambuco, Paraíba, Alagoas, Sergipe, and from northeast Minas Gerais north to southern Rio Grande do Norte.
The genus was long considered monotypic, but molecular and morphological studies have expanded it to encompass approximately 10 accepted species and 3 natural hybrids (as recognized by Plants of the World Online as of 2025). Tacinga species are characterised by their adaptation to seasonally dry environments; most grow as shrubby or sprawling cacti with flattened or cylindrical stem segments bearing areoles with spines or glochids typical of the wider Opuntioideae alliance.
Notable members include Tacinga funalis, a rope-like sprawling cactus of dry forest edges; Tacinga inamoena, which also colonises rocky outcrops; and Tacinga palmadora, widespread across northeast Brazilian dry shrublands. Multiple species are flagged as threatened by habitat loss, primarily driven by agricultural expansion and degradation of the Caatinga.
Distribution
Tacinga is endemic to northeast Brazil, distributed from northeast Minas Gerais northward through Bahia, Sergipe, Alagoas, Pernambuco, and Paraíba to southern Rio Grande do Norte. All species are associated with the Caatinga biome and its subtropical to tropical dry forests and shrublands.
Ecology
Tacinga species grow in subtropical or tropical dry forests, dry shrublands, and rocky areas — habitats characteristic of the Brazilian Caatinga. Several species, including T. funalis, T. inamoena, and T. palmadora, are listed as threatened due to ongoing habitat loss from land conversion in northeast Brazil.
Taxonomy Notes
The genus Tacinga was established by Britton & Rose in 1919. It was historically considered monotypic or near-monotypic but has been expanded through subsequent taxonomic revisions to include approximately 10 species and 3 natural hybrids. Tacinga belongs to the family Cactaceae, order Caryophyllales.
