Yam bean (Pachyrhizus erosus)

Yam Bean's turnip shaped rootThe yam bean, commonly known as Jicama (and also known as Mexican Turnip or Mexican Potato), is a climbing plant of the bean family, with alternate, three-parted leaves and a large root. They can reach a height of a few feet given suitable support and grow to a length of 20-30 feet.  The tuberous roots have a surface that is yellow or light to dark brown, papery, with a creamy yellowish white interior that resembles a raw potato.  Wild Yam Bean plants can have numerous elongated or kidney shaped tubers per plant.

Yam Bean flowerThe leaves are ovalish shape, broader than long, toothed or lobed, with three primary veins running from the base of the leaf.  The plant has a terminal leaf at the end of the stem.  This leaf will be more kidney-shaped with 3-5 veins running from its wedge-shaped base.

Yam Bean tubersThe white, pale blue, blue, or purplish flowers are pea-like in shape. The plants are often so rampant that they cover the vegetation upon which they are growing.  The fruit is a bean pod, hairy, long and oblong in shape, with separations between each of the 8-10 seeds.  The seed itself is flat, square, or rounded and olive green, brown, or reddish brown in color.

Where to Find: The yam bean is native to the American tropics, but it was carried by man years ago to Asia and the Pacific islands. Now it is commonly cultivated in these places, and is also found growing wild in forested areas. This plant grows in wet areas of tropical regions.  They taste sweet and starchy.

Edible Parts: The tubers are about the size of a turnip and they are crisp, sweet (somewhat like water chestnuts with a touch of sweetness), and juicy with a nutty flavor. They are nourishing and thirst quenching. Eat them raw or boiled. To make flour, slice the raw tubers, let them dry in the sun, and grind into a flour that is high in starch and may be used to thicken soup.

Note: The raw seeds are poisonous and all parts of the plant located above ground are toxic.

Yam Bean plant

Yam Bean leaves and flowers

Close up of Yam Bean roots/tubers

Color drawing of Yam Bean species illustrating leave, beanpods, and root

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