its fruit is 2.5-5 cm in diameter (1-2 in). the fruit is yellow when ripe but usually, it is picked green. it is smaller, seedier, has higher acidity, a stronger aroma, and a thinner rind than that of the more common persian lime. it is valued for its unique flavor compared to other lime. the key lime usually has a more tart and bitter flavor. it is perhaps most distinguished as an ingredient in the key lime pie.