From Mori et al. (in review)
Cariniana clade—(Huang et al., 2008; Prance, 1979b)—most species of this genus are very large, canopy or emergent, leptocaul trees with trunks that are cylindric to the ground, fissured external bark, thick outer bark, and reddish inner bark. The species are mostly found in lowland rain forests but sometimes occur in cerrado vegetation (e.g., Cariniana rubra). The timber of Cariniana is the most sought after by loggers, which prefer that of albarco (C. pyriformis) from northwestern South America (Colombia and Venezuela) and species of jequitiba (C. estrellensis and C. legalis) of the coastal forests of eastern Brazil. The flowers in this clade have six petals (Fig. 6E, 6L) that are membranous, zygomoprhic androecia (Figs. 6A, 6F, 6M), and the cotyledons in this group are leaf-like. Obliquely upward oriented ovules (at least in C. micrantha) are found in vertically oriented locules along the entire length of the lower septum from expanded placentae that are wider at the base than at the apex of the lower septum. For the most part, the genus differs from all others by its relatively small flowers (usually <20 mm diam.); membranous petals (only the petals of C. ianeirensis are thicker); a thin-walled staminal tube that is extended on one side to make it zygomorphic (Figs. 6A, 6F, 6M; all other Lecythidaceae with zygomorphic androecia possess a prolongation that arises from the abaxial side [Tsou & Mori, 2002] of a fleshy staminal ring); and stamens that arise from all over the inside of both the staminal tube and the extension (Figs. 6F, 6M, 6N). We have also noted that at least some species are pubescent on the filaments and the inside of the flower (Fig. 6N). To distinguish the two types of zygomorphic androecia we call the Cariniana type "staminal tube zygomorphic" whereas the type that arises from a fleshy staminal ring is called "staminal ring zygomorphic." The degree of zygomorphy varies among species, e.g., the staminal tube extension is scarcely developed in C. parvifolia (Fig. 6E) and pronounced in C. micrantha (Fig. 6A) and C. penduliflora (Fig. 6N).