Lychee

The lychee (pronounced LIE-chee or LEE-chee) is the fruit of *Litchi chinensis*, the only species in its genus within the soapberry family, Sapindaceae. The fruit has a sweet, mildly tart taste and a floral scent often compared to roses. The tree is a tall evergreen, and its fruit has a pink-red, rough, soft shell. China is the world’s leading producer, followed by India, Vietnam, other Southeast and South Asian countries, Madagascar, and South Africa. The fruit’s seeds contain methylene cyclopropyl glycine, which has been linked to hypoglycemia and encephalopathy outbreaks in undernourished children in India and Vietnam who ate lychees.

**Taxonomy**

*Litchi chinensis* is the sole member of its genus in the soapberry family. French naturalist Pierre Sonnerat named and described it in his 1782 account of his travels to the East Indies and China. The species has three subspecies, distinguished by flower arrangement, twig thickness, fruit shape, and stamen count. *Litchi chinensis* subsp. *chinensis* is the only commercially grown lychee, found wild in southern China, northern Vietnam, and Cambodia. It has thin twigs, typically six stamens per flower, and fruit with smooth or small protuberances up to 2 mm. *Litchi chinensis* subsp. *philippinensis* grows wild in the Philippines and is rarely cultivated; locally called alupag or matamata for its eye-like appearance when opened, it has thin twigs, six to seven stamens, and long, oval fruit with spiky protuberances up to 3 mm. *Litchi chinensis* subsp. *javensis* is only known in cultivation in Malaysia and Indonesia. It has thick twigs, seven to eleven stamens in sessile flower clusters, and smooth fruit with protuberances up to 1 mm.

**Description**

**Tree** *Litchi chinensis* is an evergreen tree, usually under 15 meters tall but occasionally reaching 28 meters. Its leaves are 12.5 to 20 cm long, pinnate, with four to eight alternate, elliptic-oblong to lanceolate leaflets that end abruptly in a point. The bark is grey-black, and the branches are brownish-red. The leaves resemble those of the Lauraceae family, likely due to convergent evolution, and are water-repellent (laurophyll or lauroid leaves). Flowers grow in terminal inflorescences with many panicles on the current season’s growth. These panicles form clusters of ten or more, reaching 10 to 40 cm or longer, and hold hundreds of small white, yellow, or green flowers with a distinct fragrance.

**Fruit** The tree bears fleshy fruit that matures in 80 to 112 days, depending on climate, location, and cultivar. Fruits range from round to ovoid to heart-shaped, up to 5 cm long and 4 cm wide, weighing about 20 grams. The thin, tough skin is green when immature, turning red or pink-red when ripe, and may be smooth or covered with small, sharp, rough protuberances. The rind is inedible but easy to remove, revealing a layer of translucent white flesh with a floral aroma and sweet flavor. The skin turns brown and dry after harvest. The edible part is an aril surrounding a single dark brown, inedible seed, 1 to 3.3 cm long and 0.6 to 1.2 cm wide. Some cultivars produce a high percentage of fruits with shriveled, aborted seeds called “chicken tongues,” which are prized for having more flesh and thus fetch a higher price. Because canning destroys the floral flavor, the fruit is usually eaten fresh.

**Flavor and aroma** The edible aril is juicy and translucent, with a sweet, mildly tart taste and a rose-like floral scent. Sweetness comes mainly from sucrose, glucose, and fructose; acidity from malic and citric acids. Aroma-active compounds include monoterpenes like linalool, geraniol, nerol, limonene, and cis-rose oxide (giving rose and citrus notes), along with furaneol (sweet, caramel-like), methional (cooked-potato nuance), and sulfur volatiles such as dimethyl trisulfide.

**History**

Lychee cultivation began in southern China, Malaysia, and northern Vietnam. Unofficial Chinese records mention lychees as far back as 2000 BC, but documented cultivation in China dates to 1059 AD. Wild trees still grow in parts of southern China and on Hainan Island. The fruit was a delicacy in the Chinese Imperial Court. During the Han dynasty in the 1st century, fresh lychees were a popular tribute item, so prized that a special courier service with fast horses brought them from Guangdong. In the Song Dynasty (960–1279), demand was high, as noted by Cai Xiang in his *Li chi pu* (Treatise on Lychees). The fruit was also the favorite of Emperor Li Longji’s concubine Yang Yuhuan (Yang Guifei), who had it delivered at great expense to the capital. European travelers, including a Spanish bishop, explorer, and sinologist, also took note of the lychee.