Caesalpinioideae

Caesalpinioideae is a subfamily of the legume family Fabaceae. Traditionally, it was regarded as one of the three major subfamilies of legumes, alongside Mimosoideae and Papilionoideae. In modern classifications based on molecular phylogeny, the circumscription of Caesalpinioideae has changed, and many genera formerly included here have been reassigned to other lineages such as Detarioideae. As a result, Caesalpinioideae is often treated as a narrower, monophyletic group in contemporary systems or as a paraphyletic assemblage in older treatments.

The group is largely tropical and subtropical, with species in Africa, the Americas, and Asia. It includes trees, shrubs, and climbing plants, occupying forest, woodland, and savanna habitats. Members show considerable diversity in growth form and ecological niches, contributing to tropical forest structure and dynamics.

Characteristics within Caesalpinioideae vary, but many species have compound leaves with stipules, and a range of floral forms that are often not the highly specialized papilionaceous type seen in Papilionoideae. The fruit is typically a legume, and seed mammals or birds sometimes play roles in dispersal. The subfamily displays diverse secondary chemistry and wood anatomy, supporting a variety of uses in natural and human environments.

Taxonomic status and phylogeny: Phylogenetic studies have demonstrated that the traditional Caesalpinioideae is not a single natural group, leading to reclassification that places many genera in Detarioideae or other lineages. The remaining Caesalpinioideae, when recognized, comprises a smaller, more cohesive set of genera.

Ecology and uses: The subfamily includes numerous ecologically important trees and shrubs, some of which are sources of timber, ornamental plants, tannins, or traditional medicines.