Citrus is a genus of trees and shrubs of the rue family, natural order Aurantiacese which includes the lemon, orange, lime and tangerine. They are widely cultivated for their edible fruit. They are characterized by simple ovate acuminate leaves or leaflets united by a distinct joint to the leaf-like stalk; by having the stamens united by their filaments into several irregular bundles, and by yielding a pulpy fruit with a spongy rind. Citrus medica is the citron. Other species are the lemon (Citrus limonum), the sweet orange (Citrus aurantium), the bitterorange (Citrus vulgaris), the shaddock (Citrus decumana}, and the forbidden fruit (Citrus paradisi), sometimes used as an ornamental addition to dessert. The genus Citrus furnishes the essential oils of orange and lemon peels, of orange flowers, of citronpeel, of bergamot, and oil of orange leaves - all much esteemed in perfumery. Research Citrus