The mamoncillo (Melicoccus bijugatus), also known as the mamón (although the word is considered obscene in some Spanish speaking countries where it translates roughly as cocksucker), chenet (in Trinidad and Tobago), guaya, gnep, ginep, skinnip (in Jamaica, St. Kitts) genip, guinep, ginnip, kenèp (in Haiti), quenepa (in Puerto Rico), ackee (in Barbados), Spanish lime, or limoncillo (in Dominican Republic), is a fruit-bearing tree in the soapberry family Sapindaceae, native or naturalised over a wide area of the American tropics including Central America, Mexico, Colombia, Venezuela, Dominican Republic, Guyana, Suriname and the Caribbean. It is a large tree growing up to 30 m high. The leaves are alternate, 8–5 cm long, pinnate with 4 or 6 opposite leaflets (no terminal leaflet), each leaflet 5–10 cm long.
It is grown and cultivated for its ovoid, green fruit, which grow in bunches. The fruit ripen during the summer. The fruit, similar to that of the related lychee, is classified as a drupe. A mamoncillo fruit has a tight and thin but rigid layer of skin, traditionally cracked by the teeth. Inside the skin is the tart, tangy, cream pulp of the fruit, which is sucked by putting the whole fruit inside the mouth (the seed takes most of the volume of what is inside the skin). Despite the light color of the fruit's flesh, the juice stains a dark brown color, and was often used by indigenous Arawak natives to dye cloth.
The mamoncillo has small, greenish-white, fragrant flowers in panicles. They begin to blossom from the branch tips when the rainy season begins. The mamoncillo is an example of a polygamous plant, producing bisexual flowers as well as flowers that are exclusively male or exclusively female. Occasionally, a bisexual flower will have a "dud" (sterile) anther, which limits the number of fruits produced from self-pollination when cross-pollination is possible.
Being tropical, the mamoncillo prefers warmer temperatures. Its leaves can be damaged if the temperature hits freezing point, with serious damage occurring below -4°C. Gardeners of mamoncillos should occasionally give their plants heavy watering during the summer and propagate via seeds; grafting is also used to propagate cultivars.
The mamoncillo is also commonly planted along roadsides as an ornamental tree.
According to Caribbean folk wisdom (especially in Jamaica), girls learn the art of kissing by eating the sweet flesh of this fruit, also it is said that if a girl finds two seeds then they'll have twins .