Otholobium

Otholobium is a genus of flowering plants in the pea family with over 50 named species, but several also remain undescribed so far. Species may be herbaceous perennials, subshrubs, shrubs or small trees. The alternately set leaves are accompanied by stipules and mostly consist of three leaflets, sometimes just one. The inflorescences are on short or long stalks in the axils of the leaves. Within the inflorescences, the pea-like flowers occur in groups of three, rarely of two, subtended by a bract, and each individual flower also is subtended by a narrow bract. The petals may be white, pink, purple or blue, often with a differently colored nectar guide, that may sometimes even be yellow. The seedpods contain just one, black, dark or light brown seed. Most species are restricted to the Cape Provinces of South Africa, but some occur at higher elevations in eastern Africa. Charles Stirton erected the genus in 1981. Phylogenetic studies found that the South American species are distinct from the African species, and in 2024 Egan et al. described the new genus Grimolobium to contain the eight South American species.

== Description == thumb|leaf with stipules and 3 entire leaflets in O. obliquumAs far as known, the species currently assigned to the genus Otholobium are diploids with 20 chromosomes (2n=20). They are shrubs, subshrubs or sometimes spreading herbs with alternately set leaves, each consisting of one or three entire leaflets carrying black or transparent glands, which have a wedge-shaped base and a pointed or blunt tip that is often hooked, with the main vein extended beyond the tip. Left and right of the base of the leafstalk, are two softly hairy stipules that may be partly merged with the stalk or entirely free, and are oval with a pointy tip or awl-shaped, while several veins create a striped appearance.