Buddleja brachiata is endemic to southern Brazil from Goiás to São Paulo, where it grows on disturbed areas along rivers.[1] The species was first described and named by Chamisso and von Schlechtendal in 1827.[2]
Buddleja brachiata is a small, scandent dioecious shrub with light-brown finely striated bark. The branches are subquadrangular, the youngest growth tomentulose. The leaves are subsessile, ovate, 6 - 12 cm long by 3 - 6 cm wide, glabrous and tomentulose below. The white inflorescence is 10 - 20 cm long, comprising two orders of leafy-bracted branches. The sessile flowers are borne in pairs of capitate cymules, each 0.5 - 0.7 cm in diameter, and comprising 3 - 9 flowers. The corolla is campanulate, 2 - 3 mm long.[1]
The inflorescences of the species suggest a close relationship with B. hieronymi, B. interrupta, and B. iresinoides found in the Andes; its occurrence in Brazil probably owing to the much drier conditions prevalent in the Amazon region during the Pleistocene period.[1]
The shrub is not known to be in cultivation.