The section Macrolespedeza of the genus Lespedeza is revised based on comparative studies.

Variation of floral characteristics within an individual (phenotypic plasticity), within a population (individual variation), and between populations (collective variation), and developmental changes of floral characters are described to clarify the characteristics by which species of sect. Macrolespedeza are circumscribed. The following are taxonomically significant: the shape of the lateral calyx-lobe, the shape of the apex of the lateral calyx-lobe, the ratio of the length of the lateral calyx-lobe to the length of the calyx-tube, the color of the corolla, the ratio of the length of the wing to the length of the keel-petal, the ratio of the length of the standard to the length of the keel-petal, the ratio of the length of the wing to the length of the standard, the shape of the standard, the shape of the auricle of the standard, the ratio of the length of the standard-claw to the length of the standard, the shape of the lamina of the wing, the ratio of the length of the wing-claw to the length of the wing, the shape of the lamina of the keel-petal, and the ratio of the length of the keel-petal-claw to the length of the keel-petal.

The section Macrolespedeza is divided into three series, ser. Macrolespedeza, ser. Formosae (ser. nov.), and ser, Heterolespedeza (stat. nov.). The section Macrolespedeza is represented by nine species, two subspecies, two varieties, ten forms, and two horticultural species. The species and infraspecific taxa of sect. Macrolespedeza are described in detail.