Kalamansi (Citrus microcarpa)

Calamondin or Kalamansi (scientific name: Citrus ×microcarpa) is a fruit tree in the family Rutaceae that was developed in and is very popular throughout Southeast Asia, especially the Philippines, where it is most commonly used for cooking. In the west it is variously known as acid orange, calamondin orange, Chinese Orange or Panama orange. In the Philippines it is called calamansi/kalamansî (kɐlɐmɐnˈsɪʔ) in Tagalog or the Filipino lingua franca, and limonsito in Cebuano.

It is a shrub or small tree growing to 3–6 m, and bears small citrus fruit used to flavor foods and drinks. Although sometimes described as a native of the Philippines or other areas of Southeast Asia, the tree is in fact the result of a hybrid between species in the genus Citrus and unknown in the wild. Hybrids between Citrus species have been cultivated for so long that the origins of most are obscure. It is generally held that most species in cultivation are ancient apomictic hybrids and selected cultivars of these hybrids, including crosses with segregate genera such as Fortunella and Poncirus. The calamondin is usually described as a cross between Citrus reticulata (Tangerine or Mandarin orange) and Citrus japonica Oval Kumquat group.[1]

If the segregate genus Fortunella is recognised the calamondin is treated as an intergeneric hybrid in the nothogenus ×Citrofortunella.

The fruit of the calamondin resembles a small, round lime, usually 25-35mm in diameter, but sometimes up to 45mm. It has the color of a tangerine with a very thin green or orange colored peel. Despite its appearance and aroma, the taste of the fruit itself is quite sour, though the peel is sweet. Putting the whole fruit into the mouth often leads to surprise from first-time tasters at the combination of sweet and sour. The fruit can be frozen whole and used as ice cubes in beverages like tea or ginger ale. The juice extracted by crushing the whole fruit makes a flavorful drink similar to lemonade, and a liqueur can also be made from the whole fruits, in combination with vodka and sugar. In Asia the juice is used to season fish, fowl, and pork. Kalamansî is commonly used as a condiment for dishes such as pancit bihon. Calamondin marmalade can be made in the same way as orange marmalade. Like other citrus fruits, the calamondin is high in vitamin C.

In North America, the calamondin is grown mainly as an ornamental plant; it can be especially attractive when the fruit are present. It is frost sensitive and therefore limited to warm climates (e.g., Florida, California, south Texas, and Hawaii in the U.S.). If the plant is potted, it may be brought indoors during the winter in areas with cooler climates.