Psophocarpus tetragonolobus, the winged bean, is a tropical legume whose strikingly square pods carry four winged ridges. It is rich in protein, and remarkably, nearly the whole plant is food: seeds, leaves, root tubers, and immature green pods are all eaten. Known also as goa beans and asparagus peas, it is a food-security crop in Southeast Asia, Papua New Guinea, and parts of Africa, where its many edible parts stretch the harvest. Little known in Western markets, it offers exceptional protein for a vegetable plus nitrogen-fixing ability, and agronomists and nutritionists are watching it with growing interest.