Fruit characters of cultivated citrus are among the most useful diagnostically, as the qualities of the fruit have been the primary targets of selection and breeding programs. Fruits in cultivated citrus tend to be round -- either completely spherical (e.g., some sweet oranges), longer than broad (e.g., most lemons), or broader than long (e.g., most mandarins). Fruit shape is variable in citrus relatives. Some exhibit spherical fruits (e.g., Poncirus trifoliata), whereas others may exhibit cylindrical fruits (e.g., Microcitrus australasica). Flesh color varies among and within cultivar groups. Pigmented cultivars (e.g., Hudson grapefruit) or cultivar groups (e.g., blood oranges) typically exhibit reddish fruit flesh. The degree of development of pigmentation can be variable from cultivar to cultivar, and in some groups (e.g., blood oranges) also depends on climatic conditions. Similarly to the scent of crushed young leaves, fruit flesh taste can a powerful diagnostic tool for identifying cultivar groups. Most cultivars in the broad cultivar groups of sweet oranges, grapefruits, lemons, etc., exhibit the familiar taste of varying acidity one would associate with commonly available citrus fruits in the grocery. However, a few cultivars have been developed that exhibit acidless or sweet-tasting flesh (e.g., Siamese sweet pummelo, sweet acidless lime, Lima sweet orange). Rind color and texture are also useful diagnostically. For consistency, we have chosen the same color and texture scales employed by the California Citrus Clonal Protection Program, with the addition of three character states to accommodate unusual cultivars and citrus relatives (i.e., black, red/pink, and variegated).

cylindrical fruit of Microcitrus australasica
fruit color scale
fruit rind texture scale
fruits black
fruits pink
fruits variegated