If you're a 'grow your own-er' see

http://www.edenseeds.com.au/content/default.asp - search for yam bean


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VEGETABLES
BEAN, OTHER
YAM BEAN (Pachyrrhizus erosus) (JICAMA or MEXICAN WATER CHESTNUT)
Climbing perennial from Central America. Edible part is tuber eaten raw or cooked has the texture of raw apple, sweet white crisp flesh, high quality starch, when cooked it retains its crispness and is often used in Chinese dishes in place of water-chestnut and bamboo shoots. Beans and pods are inedible, containing rotenone - a potent insecticide. Sow tubers and seeds as soon as frost is over in milder climates. Larger tubers when flowers and pods are pruned off. Space about 10-20 cm. apart. 150-180 days.
Seed count: 5/g
Seeds per packet: 22


Packet $3.00
Quantity: 20g $5.50
Quantity: 100g $30.00
Quantity: