Ceratonia siliqua Carob
This tree is of historical importance in Mediterranean countries where its pods have been used as a source of sweetening or for animal feed for centuries. The uniformity of the seeds in the carob was used as a standard for defining the carat = 200g - a unit still used for measuring gold content. Recent studies have shown that the carob seeds were subject to variation just like any other seed but the small or large ones were easy to spot and therefore removed.