The Key lime (Citrus ×aurantiifolia) is a citrus hybrid (C. micrantha x C. medica) with a globose fruit, 2.5–5 cm in diameter (1–2 in), that is yellow when ripe but usually picked green commercially.It is smaller and seedier, with a higher acidity, a stronger aroma, and a thinner rind, than that of the Persian lime (Citrus × latifolia). It is valued for its unique flavor compared to other limes, with the Key lime usually having a more sweet and bitter flavor.