Although both are citrus fruits, lemons and limes are two distinct species and grow on two different types of trees. The lemon tree is believed to have originated in India, and migrated to the Mediterranean before being carried to the New World by Columbus in 1493. Today, the two fruits complement each other and are used in similar manners.
The lemon tree (Citrus limon) grows to a height of between 10 and 20 feet and, dependent on the variety, usually is protected by sharp thorns. The leaves are light-green and may grow as long as 4.5 inches.
Lemon trees grow an oval fruit with a light yellow peel. A variety of cultivars are included within the species, ranging from the 'Meyer', which boasts a light-orange peel; to the 'Ponderosa' with its pale-green pulp; and the cold-tolerant 'Harvey'.
The lemon tree is extremely sensitive to cold damage and will defoliate if the temperature drops below 24 degrees Fahrenheit, while flowers and young fruits will typically die if the temperature falls as low as 29 F.
The tree tolerates infertile, poor soil and grows well in locations like Florida where the soil is dominated by a sandy composition; while in locations like California, it thrives in a silty, clay loam that holds water.
Two major types of lime trees exist; Mexican or Key limes (Citrus aurantifolia) and Persian or Tahiti limes (Citrus x "Tahiti"), reports the University of Florida Institute of Food and Agricultural Sciences. The Key lime grows to between 1 and 2 inches in diameter, while Tahiti limes are larger and hold more of an oval shape.
The fruit of the Mexican or Key lime is green when immature, then yellows as it ages. The flesh possesses a greenish-yellow color and tastes more acidic than a Tahiti lime.
Small and bushy, the lime tree possesses thin branches and short thorns. Thornless varieties are available but they tend to produce less fruit. Additional varieties of lime include the 'Giant Key' lime, with fruit twice the size of common Mexican limes; 'Rangpur', which closely resembles mandarins; and 'Limequats', a hybrid between the Mexican lime and kumquats.
The planting site of a lime tree should be well irrigated; it does not tolerate standing water and foot or root rot is a likely consequence in that scenario.