The revision of sects. Absus and Grimaldia in this work forms a third installment of a series projected toward a census of genus Cassia in the New World. Like its two predecessors, which dealt respectively with sect. Xerocalyx and subgenus Lasiorhegma, a group of some 250 (233 American) species characterized by the syndrome of bracteolate pedicels, elastically dehiscent pods, and short, deltately dilated seed-funicles. The large sect. Absus (163 species) is like sects. Xerocalyx and Apoucouita endemic to the Americas; monotypic sect. Grimaldia is circumtropical and weedy. The volume includes keys, descriptions, and black-and-white illustrations.