Pachyrhizus Rich. ex Dc.

Twining annual or perennial vines; stems terete; roots tuberous. Leaves pin-nate trifoliolate; leaflets entire, lobed or deeply dissected, stipels subulate, stip-ules caducous, rachis and petioles with longitudinal ridges running onto the sti-pels. Inflorescences axillary pseudoracemes, the peduncle often longer than the petiole, the flowers somewhat congested apically; bracteoles subulate, shorter than and subtending the calyx; pedicels slender, slightly longer than the calyx. Flowers blue; calyx campanulate tubular, 2-lipped, the upper 2 teeth mostly con-nate, the lower teeth acute, shorter than the tube; standard emarginate with 2 basal incurved auricles, the wings auriculate, medially adherent to the keel, the keel equalling the wings; stamens diadelphous, the anthers 10, elliptical, dorsi-fixed; ovary subsessile, multiovulate, the style incurved, sometimes forming a circle, dorsally glabrous, bearded the full length of the ventral, incurved surface. Legume oblong, compressed, nearly straight, internally septate between the seeds; seeds globose, compressed.