Sesame seed is the seed of the sesame plant (Sesamum indicum). The plant is an annual herb with foxglove-like flowers that produce pods containing the edible sesame seeds. The pods burst open with a pop when the seeds are mature. The hulls are removed as they contain oxalic acid, which gives a bitter flavor. The seeds can also be pressed for sesame oil. Besides use as a condiment, in Asia, the toasted seeds are used to make sesame paste, which is often used as a peanut butter substitute. In Middle Eastern and Asian cuisine, the untoasted seeds are used to make tahini paste.