Kumquats ( ),
The edible fruit closely resembles the orange ( Citrus x sinensis) in color, texture, and anatomy, but is much smaller, being approximately the size of a large olive. The kumquat is a fairly cold-hardy citrus.
Etymology
The English word
kumquat is a borrowing of the
Cantonese (; c=金橘), from "golden" + "orange".
Description
Kumquat plants have thornless branches and extremely glossy
leaves. They bear dainty white flowers that occur in clusters or individually inside the leaf axils. The plants can reach a height from , with dense branches, sometimes bearing small thorns.
They bear yellowish-orange fruits that are oval or round in shape. The fruits can be in diameter and have a sweet, pulpy skin and slightly acidic inner pulp. The fruit is often eaten whole by humans and has a taste that is sweet and somewhat sour.
Kumquat trees are
self-pollination.
Species
Citrus taxonomy is complicated and controversial. Different systems place various types of kumquats in different species or unite them into as few as two species. Botanically, many varieties of kumquats are classified as their own species, rather than cultivars. Historically, they were viewed as falling within the genus
Citrus, but the Swingle system of citrus taxonomy elevated them to their own genus,
Fortunella. Recent phylogenetic analysis suggests they do fall within
Citrus. Swingle divided the kumquats into two subgenera, the
Protocitrus, containing the primitive Hong Kong kumquat, and
Eufortunella, comprising the round, oval kumquat, Meiwa kumquats,
to which Tanaka added two others, the Malayan kumquat and the Jiangsu kumquat. Chromosomal analysis suggested that Swingle's
Eufortunella represent a single 'true' species, while Tanaka's additional species were revealed to be likely hybrids of
Fortunella with other
Citrus, so-called x
Citrofortunella.
One recent genomic analysis concluded there was only one true species of kumquat, but the analysis did not include the Hong Kong variety, seen as a distinct species in all earlier analyses.
In 2022, a genome-level analysis of cultivated and wild varieties drew several conclusions. The authors found support for the division of kumquats into subgenera:
Protocitrus, for the wild Hong Kong variety, and
Eufortunella for the cultivated varieties, with a divergence predating the end of the Quaternary glaciation, perhaps between two ancestral populations isolated south and north, respectively, of the Nanling mountain range. Within the latter group, the oval, round, and Meiwa kumquat each showed a level of divergence greater than between other recognized citrus species, such as between pomelo and citron, and hence each merits species-level classification. Though Swingle had speculated that the Meiwa kumquat was a hybrid of oval and round kumquats, the genomic analysis suggested instead that the round kumquat was an oval/Meiwa hybrid.
Hybrids
citrus hybrids forms of the kumquat include the following:
Origin and distribution
The kumquat plant is native to Southern
China.
[ They have been cultivated for centuries in other parts of East Asia, South Asia, and Southeast Asia.][ They were introduced into Europe in 1846 by Robert Fortune, collector for the London Horticultural Society,][
]
Cultivation
Kumquats are much hardier than citrus plants such as oranges. Sowing seeds in the spring is ideal because the temperature is pleasant, with more chances of rain and sunshine. This also gives the tree enough time to become well established before winter. Early spring is the best time to transplant a sapling. They do best in direct sunlight (needing 6–7 hours a day) and are planted directly in the ground. Kumquats do well in USDA hardy zones 9 and 10 and can survive in temperatures as low as . On trees mature enough, kumquats will form in about 90 days.
In cultivation in the United Kingdom, Citrus japonica has gained the Royal Horticultural Society's Award of Garden Merit
Propagation
Kumquats do not grow well from seeds and so are vegetatively propagated by using citrus rootstock of another citrus fruit,[
]
Varieties
The Nordmann seedless is a seedless cultivar of the Nagami kumquat ( Citrus margarita). It is similar to Nagami but with a slightly different shape and lighter skin.
The C entennial Variegated is another cultivar of the Nagami kumquat. It originated from the open pollination of a Nagami kumquat tree. The fruits are striped light green and yellow when underripe, and turn orange and lose their stripes when they ripen. They are oval-shaped, necked, 2.5 inches long, and have a smooth rind. They mature in winter.[ and by their lack of thorns.
]
The Puchimaru kumquat is a seedless or virtually seedless Japanese kumquat cultivar. It is resistant to citrus canker and citrus scab. The fruit weighs 11–20 grams and is ellipsoid in shape. It has a dark orange rind, which is 4 millimeters thick. The juice content is relatively low. The oil glands are somewhat large and conspicuous. It ripens in January.
Uses
Nutrition
A raw kumquat is 81% water, 16% , 2% protein, and 1% fat (table). In a reference amount of , raw kumquat supplies of food energy and is a rich source of vitamin C (49% of the Daily Value), with no other in significant content (table).
Essential oil
The essential oil of the kumquat peel contains much of the aroma of the fruit, and is composed principally of limonene, which makes up around 93% of the total.[
]
== Gallery ==
See also
Further reading
External links
