N. Rakotonirina & R. Ramananjanahary (2009): Breonia longipetiolata Havil. is considered doubtful and Breonia mayrorii Setch. is an excluded species (Razafimandimbison, S.G., 2002). Generic evaluation is based on the specimens from TAN, TEF herbaria.
C.M. Taylor VIII 2011: Breonia is endemic to Madagascar and perhaps the Mascarene Islands (the type collection of B. chinensis is from Mauritius but apparently was only cultivated there). It is characterized by its shrub or tree habit, interpetiolar stipules, axillary inflorescences with the head globose and solitary, small flowers that are fused together by their ovaries, and syncarp fruits. The developing inflorescences of most species are completely enclosed by calyptrate deciduous bracts. The calyx lobes are typically obconical, stout, and truncate to rounded and densely pubescent on their tops. The fruits appear to be fleshy, if not always soft. Breonia is very similar to Janotia, Gyrostipula, and Breonadia, and these have often been confused; for their separation, see the key to Breonia and similar genera below on this page. Razafimandimbison & Bremer (2001) presented an analysis based on molecular sequence data of the relationships of Breonia, which they found grouped with Gyrostipula and Janotia, and these all related to Breonadia.
The taxonomic and nomenclatural history of Breonia is unusually complicated or confused; the revision of Razafimandimbison (2002) is followed here for both of these aspects. Particularly problematic and controversial here is the identity of Anthocephalus chinensis: taxonomists studying the Madagascar Rubiaceae in detail have all used this name for an endemic species of Madagascar that is here called B. chinensis and have considered this name based on the type specimen of Cephalanthus chinensis from Mauritius, where many trees from Madagascar were cultivated for study, while taxonomists working on Asian Rubiaceae have instead used this name for a widespread large tree that is cultivated for lumber. These various taxonomists do not disagree about the identity of the specimen from Mauritius, but about whether this is the type specimen for this name. This situation is problematic because the descriptions of Cephalanthus chinensis and Anthocephalus indicus clearly apply to different species even though Anthocephalus indicus was supposedly a new name for Cephalanthus chinensis. Razafimandimbison (2002) applied the name Cephalanthus chinensis to the Madagascar tree and called the Asian lumber tree Neonauclea cadamba; recent authors have more often called the Asian lumber tree Neolamarckia cadamba (Roxb.) Bosser.