Input (grade 8): The Key lime (Citrus aurantifolia) is a citrus species with a globose fruit, 2.5 - 5 cm in diameter (1 - 2 in), that is yellow when ripe but usually picked green commercially.
Output (grade 6): C. aurantiifolia is a shrubby tree, that grows to 5 m (16 ft), with many thorns.