30-487: Dimocarpus longan , commonly known as the longan ( / ˈ l ɒ ŋ ɑː n / ) and dragon's eye , is a tropical tree species that produces edible fruit. It is one of the better-known tropical members of the soapberry family Sapindaceae , to which the lychee and rambutan also belong. The fruit of the longan is similar to that of the lychee, but is less aromatic in taste. The longan (from Vietnamese long nhãn or Cantonese lùhng ngáahn 龍眼 , literally 'dragon eye'),
60-555: A nectar disc between the petals and stamens, their filaments are often hairy. The most frequent number is eight, in two rings of four. The gynoecium contains two or three carpels , sometimes up to six. The usually single style has a lobed stigma. Most often they are pollinated by birds or insects , with a few species pollinated by wind . Ripe fruits may be fleshy or dry. They may be nuts , berries , drupes , schizocarps , capsules ( Bridgesia ), or samaras ( Acer ). The embryos are bent or coiled, without endosperm in
90-473: A fruit-bearing tree's leaves or branches. Algal spot on longan plants, like many other tropical fruits, is caused by Cephaleuros virescens . An oomycete disease that causes blight on leaves and foliage of a plant and affects the related lychee, Phytophthora palmivora , can also appear on both longan plants and fruit, particularly in the Thailand region. When affecting longan, it can create brown spots on
120-467: A thirty-year breeding program in 2001. Studies in 2015 that aimed to aid longan breeding efforts discovered that −20 degrees Celsius is the optimal temperature for long-term storage of longan pollen, a key ingredient in enabling longan breeding programs. Raw longan fruit is 83% water, 15% carbohydrates , 1% protein , and contains negligible fat (table). In a 100 g (3.5 oz) reference amount, raw longan supplies 60 calories of food energy, 93% of
150-548: Is believed to originate from the mountain range between Myanmar and southern China. Other reported origins include Indonesia, India, Sri Lanka , upper Myanmar , north Thailand, Kampuchea (more commonly known as Cambodia), north Vietnam and New Guinea . Its earliest record of existence draws back to the Han dynasty in 200 BCE . The emperor had demanded lychee and longan trees to be planted in his palace gardens in Shaanxi , but
180-455: Is different from lychees; while longan has a drier sweetness similar to dates, lychees are often messily juicy with a more tropical, grape-like sour sweetness. Dried longan are often used in Chinese cuisine and Chinese sweet dessert soups. In Chinese food therapy and herbal medicine , it is believed to have an effect on relaxation. In contrast with the fresh fruit, which is juicy and white,
210-452: Is divided into four subfamilies, Dodonaeoideae (about 38 genera), Sapindoideae (about 114 genera), Hippocastanoideae (5 genera) and Xanthoceroideae (1 genus). The largest genera are Serjania (about 220 species), Paullinia (about 180 species), and Allophylus (about 200 species) in the tropical Sapindoideae and Acer (about 110 species) in the temperate Hippocastanoideae. The largely temperate genera formerly separated in
240-442: Is picked early in the day to minimize water loss and to prevent high heat exposure, which would be damaging. The fruit is then placed into either plastic crates or bamboo baskets and taken to packaging houses, where the fruit undergo a series of checks for quality. The packaging houses are well-ventilated and shaded to prevent further decay. The process of checking and sorting are performed by workers instead of machinery. Any fruit that
270-688: Is so named because the black seed within the shelled fruit creates the appearance of an eyeball. The plant is native to tropical Asia and China. Depending upon climate and soil type the tree may grow to over 30 metres (100 ft) in height, but it typically stands 9–12 m (30–40 ft) in height and the crown is round. The trunk is 80 cm ( 2 + 1 ⁄ 2 ft) thick with corky bark . The branches are long and thick, typically drooping. The leaves are oblong and blunt-tipped, usually 10–20 centimetres (4–8 in) long and 5 cm (2 in) wide. The leaves are pinnately compounded and alternate. There are 6 to 9 pairs of leaflets per leaf and
300-435: Is split, under-ripe, or decaying is disposed of. The remaining healthy fruit is then prepared and shipped to markets. Many companies add preservatives to canned longan. Regulations control the preserving process. The only known preservative added to canned longan is sulfur dioxide , to prevent discoloration. Fresh longan that is shipped worldwide is exposed to sulfur fumigation . Tests have shown that sulfur residues remain on
330-450: Is the aptly named longan decline , which is largely prevalent in Thailand, with reports finding that it could affect up to 40% of longan trees alone. Affected trees are more vulnerable to common tree pests and algae, and often bear low-quality fruit unworthy of yield. Algal spot is another plant disease that can affect longan plants and trees. Common among tropical fruits, the disease mainly takes form as red-orange algae that can appear on
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#1732780519031360-575: The Daily Value (DV) of vitamin C , 11% DV of riboflavin , and no other micronutrients in appreciable quantities (table). The fruit is sweet, juicy, and succulent in superior agricultural varieties. The seed and the peel are not consumed. Apart from being eaten raw like other fruits, longan fruit is also often used in Asian soups, snacks, desserts, and sweet-and-sour foods, either fresh or dried, and sometimes preserved and canned in syrup. The taste
390-641: The Philippines , Bangladesh , Mauritius , the United States, and Australia. Longan, like its sister fruit lychee, thrives in humid areas or places with high rainfall, and can grow on most types of soil that does not induce issues with water drainage. Ample temperatures are also instrumental in longan growth: while longan can resist small stretches of cool temperatures, they can be damaged or killed in longer stretches of temperatures as high as −2 degrees Celsius. Younger plants tend to be more vulnerable to
420-627: The seed is large and black with a circular white spot at the base. This gives the illusion of an eye. The flesh has a musky, sweet taste, which can be compared to the flavor of lychee fruit. The seed is round, hard, and has a lacquered appearance. The longan tree is somewhat sensitive to frost . While the species prefers temperatures that do not typically fall below 4.5 °C (40 °F), it can withstand brief temperature drops to about −2 °C (28 °F). Longan trees prefer sandy soil with mild levels of acidity and organic matter . Longans usually bear fruit slightly later than lychees. The longan
450-569: The World Online lists: The wild longan population have been decimated considerably by large-scale logging in the past, and the species used to be listed as Vulnerable on the IUCN Red List . If left alone, longan tree stumps will resprout and the listing was upgraded to Near Threatened in 1998. Recent field data are inadequate for a contemporary IUCN assessment. Plant based diseases can affect both longan fruits and their trees, and
480-435: The cold than those more mature. During harvest, pickers must climb ladders to carefully remove branches of fruit from longan trees. Longan fruit remain fresher if still attached to the branch, so efforts are made to prevent the fruit from detaching too early. Mechanical picking would damage the delicate skin of the fruit, so the preferred method is to harvest by hand. Knives and scissors are the most commonly used tools. Fruit
510-529: The easy growth of longan trees. This jump-started the longan industry in these locations. Despite its long success in China, the longan is considered to be a relatively new fruit to the world. It has only been acknowledged outside of China in the last 250 years. The first European acknowledgment of the fruit was recorded by João de Loureiro , a Portuguese Jesuit botanist, in 1790. The first entry resides in his collection of works, Flora Cochinchinensis . Plants of
540-911: The families Aceraceae ( Acer , Dipteronia ) and Hippocastanaceae ( Aesculus , Billia , Handeliodendron ) were included within a more broadly circumscribed Sapindaceae by the Angiosperm Phylogeny Group . Recent research has confirmed the inclusion of these genera in the Sapindaceae. The Sapindaceae include many species of economically valuable tropical fruit , including the lychee , longan , pitomba , guinip/mamoncillo , korlan , rambutan , pulasan , and ackee . Other products include guaraná , soapberries , and maple syrup . Some species of maple and buckeye are valued for their wood, while several other genera, such as Koelreuteria , Cardiospermum , and Ungnadia , are popular ornamentals . Schleichera trijuga
570-469: The flesh of dried longans is dark brown to almost black. Once fermented, it can be made into longan wine . Sapindaceae The Sapindaceae are a family of flowering plants in the order Sapindales known as the soapberry family . It contains 138 genera and 1,858 accepted species. Examples include horse chestnut , maples , ackee and lychee . The Sapindaceae occur in temperate to tropical regions, many in laurel forest habitat, throughout
600-600: The fruit in an erratic fashion, and can also cause longan to drop prematurely from the plant. Early symptoms can also include a dark necrosis on the plant itself. Stem-end rot is a disease common amongst litchi and longan, and causes browning and rot on the stem of the fruit. Longan also suffer from various decay-accelerating fungi. An oomycete disease that affects the related lychee, Phytophthora litchii , also afflicts D. longan . Currently, longan crops are grown in southern China, Taiwan , northern Thailand, Malaysia, Indonesia, Cambodia, Laos, Vietnam, India, Sri Lanka,
630-441: The fruit skin, branches, and leaves for a few weeks. This violates many countries' limits on fumigation residue, and efforts have been made to reduce this amount. Longan is found commonly in most of Asia, primarily in mainland China, Taiwan, Vietnam and Thailand. China, the main longan-producing country in the world, produced about 1.9 million metric tons (2.1 million short tons) of longan in 2015–2017, accounting for 70% of
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#1732780519031660-416: The panicle; staminate (functionally male), pistillate (functionally female), and hermaphroditic flowers. Flowering occurs as a progression. The fruit are circular and about 2.5 cm (1 in) wide; they hang in drooping clusters. The shell is tan, thin, and leathery with tiny hairs; when firm, it can be squeezed (as in the cracking of a sunflower seed ) to shell the fruit. The flesh is translucent, and
690-431: The plants failed. Four hundred years later, longan trees flourished in other parts of China like Fujian and Guangdong , where longan production soon became an industry. Later on, due to immigration and the growing demand for nostalgic foods, the longan tree was officially introduced to Australia in the mid-1800s, Thailand in the late-1800s, and Hawaii and Florida in the 1900s. The warm, sandy-soiled conditions allowed for
720-634: The seed, and frequently with an aril . The Sapindaceae are related to the Rutaceae , and both are usually placed in an order Sapindales or Rutales , depending on whether they are kept separate and which name is used for the order. The most basal member appears to be Xanthoceras . Some authors formerly maintained some or all of Hippocastanaceae and Aceraceae , however this resulted in paraphyly . The former Ptaeroxylaceae , now placed in Rutaceae, were sometimes placed in Sapindaceae. The family
750-534: The severity of these diseases can range from harmless cosmetic damage to rendering to the fruit inedible. The most prevalent disease among longan plants is witch's broom , which can be found in all major longan-producing Asian territories, including China, Thailand, and Vietnam. Witch's broom deforms longan skin, and at times causes the plant to prematurely drop its fruit, similar to the Phytophthora palmivora . Another common disease that longan trees can carry
780-819: The temperate maples ( Acer ), Aesculus , and a few other genera are opposite. They are most often pinnately compound , but are palmately compound in Aesculus , and simply palmate in Acer . The petiole has a swollen base and lacks stipules . Some genera and species have laurel forest foliage due to convergent evolution . The flowers are small and unisexual , or functionally unisexual, though plants may be either dioecious or monoecious. They are usually found in cymes grouped in panicles . They most often have four or five petals and sepals (petals are absent in Dodonaea ). The stamens range from four to 10, usually on
810-435: The upper surface is wavy and a dark, glossy-green. The longan tree produces light-yellow inflorescences at the end of branches. The inflorescence is commonly called a panicle ; they can be 10–46 cm (4–18 in) long, and widely branched. The small flowers have 5 to 6 sepals and petals that are brownish-yellow. The flower has a two-lobed pistil and 8 stamen . There are three flower types, distributed throughout
840-419: The world's longan production and more than 50% of the world's longan plots. Vietnam and Thailand produced around 500 and 980 thousand metric tons (550 and 1,080 thousand short tons), respectively. Like Vietnam, Thailand's economy relies heavily on the cultivation and shipments of longan as well as lychee. This increase in the production of longan reflects recent interest in exotic fruits in other parts of
870-519: The world. However, the majority of the demand comes from Asian communities in North America, Europe and Australia. While longan yields average out to 2 to 5 tonnes per hectare, there have been observed yields of up to 19.5 tonnes per ha in Israel . Advancements in selective breeding have allowed scientists to find a strain of longan containing a "high proportion of aborted seeds" at the end of
900-459: The world. Many are laticiferous , i.e. they contain latex , a milky sap , and many contain mildly toxic saponins with soap -like qualities in either the foliage and/or the seeds, or roots. The largest genera are Serjania , Paullinia , Allophylus and Acer . Plants of this family have a variety of habits, from trees to herbaceous plants to lianas . The leaves of the tropical genera are usually spirally alternate, while those of
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