Key lime

Appearance

''C. aurantiifolia'' is a shrubby tree, to 5 m , with many thorns. Dwarf varieties exist that can be grown indoors during winter months and in colder climates. Its trunk, which rarely grows straight, has many branches, and they often originate quite far down on the trunk. The leaves are ovate, 2.5–9 cm long, resembling orange leaves . The flowers are 2.5 cm in diameter, are yellowish white with a light purple tinge on the margins. Flowers and fruit appear throughout the year, but are most abundant from May to September in the Northern Hemisphere.

When in contact with the skin, the Key lime can sometimes cause phytophotodermatitis, in which a chemical reaction makes the skin extra sensitive to ultraviolet light

Naming

The English word "lime" was derived, via Spanish then French, from the Arabic word ''līma'' . "Key" is from Florida Keys, where the fruit is naturalized. The Oxford English Dictionary dates the first use of "key lime" to 1905, in an issue of ''Country Gentleman'', which described the fruit as "the finest on the market. It is aromatic, juicy, and highly superior to the lemon."

Defense

The method of cultivation greatly affects the size and quality of the harvest. Trees cultivated from seedlings take 4–8 years before producing a harvest. They attain their maximal yield at about 10 years of age. Trees produced from cuttings and air layering bear fruit much sooner, sometimes producing fruit a year after planting. It takes approximately 9 months from the blossom to the fruit.
When the fruit have grown to harvesting size and begin to turn yellow they are picked and not clipped. To achieve produce of the highest market value, it is important not to pick the fruit too early in the morning; the turgor is high then, and handling turgid fruit releases the peel oils and may cause spoilage.

Evolution

This particular cultivar is a citrus hybrid, likely ''Citrus micrantha'' x ''Citrus medica'' .

''C. aurantiifolia'' is native to Southeast Asia. Its apparent path of introduction was through the Middle East to North Africa, then to Sicily and Andalucia and via Spanish explorers to the West Indies, including the Florida Keys. From the Caribbean, lime cultivation spread to tropical and subtropical North America, including Mexico, Florida, and later California.

Since the North American Free Trade Agreement came into effect, many Key limes on the US market are grown in Mexico, Central America and South America. They are also grown in Texas, Florida, and California.