Key Lime

Key Lime, also called Mexican or West Indian lime, is identified by UF/IFAS as Citrus × aurantiifolia. UF/IFAS reports that Spanish and Portuguese explorers brought it to the Americas in the early sixteenth century; the exact year and route remain unspecified. The UCR collection’s CRC 1710 entry documents a 1927 receipt of budwood, not the cultivar’s origin.^⁠[4]⁠[1]

The UCR collection describes very small, round-to-oval fruit with a very thin, adherent rind and greenish-yellow flesh that is tender, juicy, highly acidic and aromatic; it reports moderate seediness. UF/IFAS gives a broader size range of 1.5–2 inches and 10–15 seeds, while NC State also describes the fruit as spherical, seedy, juicy and aromatic. Separate video descriptions range from a sharply acidic mixed-haul sample to a general nursery description of slight tartness.^{⁠[1]⁠[4]⁠[5]⁠[9]⁠[11]}

Sources describe Key Lime as a small to medium, bushy or spreading, thorny shrub or small tree; NC State lists mature dimensions of 6–13 feet tall by 5–15 feet wide. UCR reports flowering through the year, mainly in spring and late summer, and a crop that is somewhat everbearing but mainly in winter. UF/IFAS describes seedlings as generally true-to-type because of polyembryony and lists cuttings, air-layers, budding and grafting. Key Lime is cold-sensitive; UF/IFAS warns of leaf injury around 30–32°F and wood damage below 29°F as general guidance; a grower’s advice to shelter a potted tree near 40°F is not an observed damage threshold. Other single-container reports give estimates rather than standardized size or yield measurements.^{⁠[1]⁠[4]⁠[5]⁠[6]⁠[7]}

Because they produce distinctive symptoms when infested with the tristeza virus, West Indian lime seedlings are widely used as an indicator in the detection of this disease.^⁠[1]