persian lime ("citrus x latifolia"), also known as tahiti lime or bearss lime is a kind of citrus fruit. it is the primary citrus fruit grown commercially in the u.s. it is sold simply as a "lime". the fruit is about 6 cm in diameter. very often, it has slightly nippled ends. it is usually sold quite green, although it yellows as it reaches full ripeness. it is larger, thicker-skinned, and less aromatic than the key lime. the key lime is grown more often worldwide. the persian lime is bigger than the key lime, and has fewer seeds. the plant is also hardier, and has no thorns on the bushes. the fruit also has a longer shelf life.