Citrus

Citrus refers to a group of flowering plants in the Rutaceae family that bear edible fruits. The genus includes many cultivated varieties derived from several species, with oranges, lemons, limes, mandarins, and grapefruits among the most familiar. Common cultivated species include Citrus sinensis (sweet orange), Citrus limon (lemon), Citrus aurantiifolia (lime), Citrus reticulata (mandarin), and Citrus paradisi (grapefruit); pomelo, Citrus maxima, is another large fruit, and kumquats are sometimes placed within the group.

These plants are typically evergreen trees or shrubs native to subtropical and tropical South and Southeast Asia, but they are now grown worldwide. The fruit is a hesperidium with a leathery rind, a white mesocarp (pith), and segmented pulp. The rind contains essential oils, especially limonene, used in flavoring, fragrances, and cleaning products.

Cultivation emphasizes warm climates, well-drained acidic soils, and reliable irrigation. Many varieties are produced by grafting cultivars onto rootstocks to improve disease resistance and vigor. Commercial production often integrates pruning, fertilization, pest management, and disease control, with particular attention to citrus greening (huanglongbing) and other pathogens.

Uses include fresh eating, juice production, and processing into marmalades and flavorings. Citrus fruits are notable sources of vitamin C and dietary fiber, and their peels yield essential oils used in foods, fragrances, and cleaners.

History and distribution: origin in Southeast Asia with early cultivation in the Mediterranean and tropical regions; global spread followed trade and colonization, leading to the diverse citrus industry seen today.