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Why winged bean?

A useful garden vegetable

The winged bean is a useful semi-domesticated legume, distributed widely, but not intensively, throughout the humid tropics of Asia and Melanesia. In parts of Myanmar (Burma) and Papua New Guinea there are varieties that produce edible tubers on the scale of a field crop. More commonly, winged beans are grown for their winged fruits, and then, one or two vigorous vines are sufficient to meet individual household needs. All parts of the plant have a high crude protein content, which is valuable from a nutritional point of view.

The edible parts of winged bean

Winged bean parts


Plant part

Highest annual yield recorded (kg/ha)

Composition (per 100 g fresh weight)

Where consumed

How consumed

Green pods


2-3 g Protein

SE Asia; New Guinea

Steam-fried; soups; salads

Root tubers


11 g Protein,
31 g Carbohydrate

New Guinea

Steam-roasted; boiled



30-37 g Protein, 15-18 g Fat

Indonesia; New Guinea

in tempeh



5-8 g Protein,
3-21 i.u.
Vitamin A

New Guinea

Steamed; boiled



6 g Protein

New Guinea

Steamed; salads

Crop Evolution

What makes the plant interesting from the viewpoint of those who study crop evolution, is its enigmatic geographical distribution: the winged bean is an agricultural plant of Asia, whereas the only related species in the wild, are restricted to Africa. No wild progenitor of winged bean is found in Asia, whereas, apparently, the winged bean had never been grown as a crop in Africa until the nineteenth century.

This kind of biogeographical conundrum is not uncommon in the study of domesticated plants and animals, but the winged bean makes a particularly useful subject to study, because its minor agricultural importance has kept its genetic heritage relatively undisturbed by colonial migrations and by modern plant breeding methods.

The purpose of this case study, then, is to use the story of the winged bean to demonstrate how the student of crop evolution sets about answering questions of the kind: "from where did this crop arise?"

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