Key lime
A small, acidic lime valued for its aromatic flavor.
The Key lime, also known as West Indian lime, Mexican lime, or Egyptian lime (Citrus × aurantiifolia), is a type of lime. It originated as a natural hybrid between Citrus micrantha (a wild papeda) and Citrus medica (citron). It is valued for its characteristic flavor and is best known as the flavoring ingredient in Key lime pie, taking its name from the Florida Keys where it was naturalized.
- scientific_name
- Citrus × aurantiifolia
- type
- Lime
- origin
- Southeast Asia (natural hybrid)
- known_for
- Flavoring ingredient in Key lime pie
- height
- Up to 5 metres (16 feet)
- fruit_diameter
- 3–6 cm
Lore & Background
The Key lime is a shrubby tree growing to 5 metres with many thorns. Its leaves are ovate, resembling orange leaves, and its flowers are yellowish white with a light purple tinge. The fruit is spherical, 3–6 cm in diameter, with a very thin, glandular peel and yellow-green pulp that is very acidic, juicy, and fragrant. The tree flowers and fruits throughout the year, most abundantly from May to September in the Northern Hemisphere. The Key lime is usually picked while still green but turns yellow when ripe. Skin contact can sometimes cause phytophotodermatitis, making the skin sensitive to ultraviolet light. The Key lime is native to Southeast Asia and spread through the Middle East to North Africa, then to Sicily and Andalucia, and via Spanish explorers to the West Indies, including the Florida Keys. Henry Perrine is credited with introducing the Key lime to Florida. In the late 19th century in California, Mexican limes were more highly valued than lemons, while in Florida they were considered weeds. Since the North American Free Trade Agreement, most Key limes on the U.S. market have been grown in Mexico, Central America, and South America, though they are also grown in Texas, Florida, and California.
Reader's Guide
The Key lime is significant as the parent of several other lime varieties, most notably the Persian lime (Citrus × latifolia), a triploid progeny of a Key lime-lemon cross that is the most widely produced lime globally. Other hybrids include the seedy Tanepeo, Coppenrath, Ambilobe, and Mohtasseb limes, as well as the Madagascar lemon, Kirk lime, New Caledonia and Kaghzi limes, and the tetraploid Giant Key lime. The Key lime's tendency to form diploid gametes offers potential for greater hybrid diversity, which may reduce disease risk from the limited diversity of current commercial limes. Its legacy is tied to the Florida Keys and Key lime pie, though its cultivation has spread globally. The fruit is also processed into black lime, a condiment used in the Middle East, by boiling in brine and drying. Postharvest handling is critical, as shelf life is limited; storage at 9–10 °C with high humidity is ideal, and coatings like coconut oil can improve shelf life for small-scale farmers.
Did You Know?
- The Key lime originated as a natural hybrid between Citrus micrantha (a wild papeda) and Citrus medica (citron).
- Skin contact with the Key lime can cause phytophotodermatitis, making skin sensitive to ultraviolet light.
- Key limes are made into black lime by boiling them in brine and drying, a condiment used in the Middle East.
Frequently Asked Questions
What is Key lime?
Key lime (Citrus × aurantiifolia) is a small, sharply acidic citrus fruit that also goes by the names West Indian lime, Mexican lime, and Egyptian lime. It is a true lime species celebrated for its intense, aromatic flavor profile.
Where did Key lime originally come from?
Key lime is a natural hybrid that first arose in Southeast Asia, resulting from a cross between the wild papeda (Citrus micrantha) and citron (Citrus medica). It later became naturalized in the Florida Keys, which is where it picked up its most widely used common name.
What is Key lime most famous for?
Key lime is best known as the signature flavoring in the classic dessert Key lime pie. Its small size and punchy, aromatic acidity make it a go-to ingredient in cooking and baking.
How big does a Key lime tree and its fruit get?
A mature Key lime tree can grow up to roughly five metres (about 16 feet) tall. The individual fruits are quite small, typically ranging from three to six centimetres in diameter.
What does the '×' in Key lime's scientific name mean?
The multiplication sign in Citrus × aurantiifolia signals that the species is a natural hybrid rather than a pure, single-parent lineage. It reflects the fruit's origin as a cross between two distinct citrus ancestors, papeda and citron.
More in Peppers & Citrus Fruits 1-17
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record