[Guar Phalli, Guvar, Goruchikkudu (India); Cyamopsis tetragonoloba]
This small bean probably originated in India where 80% of the world's supply is grown. They are also grown in California, mostly for guar gum but some are diverted to Indian markets. They are sold when mature but the pods are still green so they can be cooked as a vegetable. These beans grow to about 4 inches long (10 cm).
Guar gum, with about 7 times the thickening power of corn starch, is made by grinding mature beans. It is widely used in commercial food processing and for various industrial uses.
This gum became an important component of "Fraking" mix for extracting oil from shale in North America. Demand and price soared, caused a huge boom in guar growing in India. The price got so high, alternatives were found, causing a tremendous deflation in the price and great hardship for guar growers in India.
More on Varieties of Beans.