Tamarind, the sweet and sour fruit of the tamarind tree, is native to Asia and northern Africa and is also grown in the Caribbean. Like lemon, tamarind brings an acidic zing to food. Tamarind, along with a host of other flavors, gives Worcestershire sauce its je ne sais quoi. Sometimes, tamarind seeds are roasted and used as flavoring. In parts of East Africa, tamarind is the base of refreshing iced drinks and sweets.