Trees, shrubs, and woody vines; stipules borne on outer edge of adaxial face of petiole, at or somewhat above its base, distinct, persistent. Inflorescence an elongated pseudoraceme. Petals mostly bright yellow with the claw sometimes turning red in age, pale yellow to whitish in a few species; stamens 10, all fertile; anthers equal or subequal, the connective not exceeding the locules; pollen globally symmetrical; receptacle glabrous between androecium and gynoecium; gynoecium comprising 2 or 3 carpels; ovary with carpels completely connate, the locules as many as carpels, all fertile.
Distribution: neotropics (five genera) and palaeotropics (Tristellateia).
The Bunchosia clade is very strongly supported by molecular evidence—see the phylogenetic tree above, with bootstrap values above the branches, which is from Davis & Anderson (2010 [pdf]). On the other hand, in their morphology these genera are extremely diverse, especially in their fruits, which include dry and fleshy fruits, dehiscent and indehiscent fruits, and dry fruits with the walls smooth or bearing several different kinds of outgrowths. Because of this fruit diversity, Niedenzu (1928) placed these six genera in four different tribes, and even in the two cases where he put pairs of genera in the same tribe (Heladena and Thryallis, Echinopterys and Henleophytum), our tree puts the members of those pairs in different subclades, indicating that they are not sisters in either case. Most of the shared characters given in the description above (pseudoracemose inflorescences, yellow petals, ten fertile stamens with the anthers ± alike) are probably symplesiomorphic in this clade. One possible synapomorphy for the clade is the distinct, persistent stipules borne adaxially on the base of the petiole. The pollen is also similar and relatively derived, as was noted for Bunchosia, Heladena, Henleophytum, and Thryallis by Lowrie (1982). The beauty of the Bunchosia clade is that it serves as a convenient, if surprising, repository for a group of genera that are all more or less isolated in their morphological characters, a sort of refuge for derived groups that would otherwise have no home.
Four of the genera in this clade (Bunchosia, Echinopterys, Heladena, and Henleophytum) have the styles weakly to strongly coherent for part or all of their length in some or all species. That is a rare phenomenon in the Malpighiaceae, which suggests that some degree of coherence of the styles may have been ancestral in the clade. Against that hypothesis are the facts that there is no sign of such coherence in Thryallis or Tristellateia, and a number of species of Bunchosia have the styles completely distinct, so if coherent styles were ancestral in Bunchosia they have reverted repeatedly to the symplesiomorphic condition of the family, distinct styles.