Lycium

Lycium
African boxthorn (Lycium ferocissimum)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Solanales
Family:	Solanaceae
Subfamily:	Solanoideae
Tribe:	Lycieae[1]
Genus:	Lycium L.[2]
Species
About 70-80, see text
Synonyms
Cantalea Raf. Evoista Raf. Jasminoides Duhamel Oplukion Raf. Panzeria J.F.Gmel. Teremis Raf.[2]

Lycium is a genus of flowering plants in the nightshade family, Solanaceae. The genus has a disjunct distribution across the globe, with species occurring on most continents in temperate and subtropical regions. South America has the most species, followed by North America and southern Africa. There are several scattered across Europe and Asia, and one is native to Australia.^[3]

The generic name is derived from the Greek word λυκιον (lycion), which was applied by Pliny the Elder (23-79) and Pedanius Dioscorides (ca. 40-90) to a plant known as dyer's buckthorn. It was probably a Rhamnus species and was named for Lycia, the province in which it grew.^[4] General common names for the genus include box-thorn,^[5] desert-thorn, and wolfberry.^[6]

There are about 70^[3] to 80^[7][8] species.

Description

Lycium barbarum

Lycium are shrubs, often thorny, growing 1 to 4 meters tall. The leaves are small, narrow, and fleshy, and are alternately arranged, sometimes in fascicles. Flowers are solitary or borne in clusters. The funnel-shaped or bell-shaped corolla is white, green, or purple in color. The fruit is a two-chambered, usually fleshy and juicy berry which can be red, orange, yellow, or black. It may have few seeds or many.^[5][7] Most Lycium have fleshy, red berries with over 10 seeds, but a few American taxa have hard fruits with two seeds.^[8]

While most Lycium are monoecious, producing bisexual flowers with functional male and female parts, some species are gynodioecious, with some individuals bearing bisexual flowers and some producing functionally female flowers.^[9]

Uses

Lycium has been known to European herbalists since ancient times and species were traded from the Far East to Europe by the Romans already, for example via Ariaca and the port of Barbarikon near today's Karachi, as mentioned in the Periplus of the Erythraean Sea. In his Naturalis historia, Pliny the Elder describes boxthorn as a medicinal plant recommended as a treatment for sore eyes and inflammation, as does Pedanius Dioscorides in his P. Dioscoridae pharmacorum simplicium reique medicae.^[10]

Boxthorn is mentioned in the biblical Book of Proverbs as besetting the paths of the wicked (Proverbs 22:5). In his 1753 publication Species Plantarum, Linnaeus describes three Lycium species: L. afrum, L. barbarum, and L. europaeum.^[10]

L. barbarum

Lycium, particularly L. barbarum, have long been used in traditional Chinese medicine to treat conditions such as male infertility.^[11] The fruit of L. barbatum and L. chinense, known as Goji, has recently become popular in western cultures for its supposed promotion of weight loss and general longevity.^[12] The Chinese tonic Fructus Lycii (Gou-Qi-Zi) is made of the fruit of any of several Lycium species, and is used as a supplement, especially for eye health.^[13]

Ecology

Lycium species mostly occur in arid and semi-arid climates, and a few are known from coastal zones in somewhat saline habitat types.^[3]

Invasive species include L. ferocissimum, which was introduced to Australia and New Zealand and has become a dense, thorny pest plant there. It injures livestock, harbors pest mammals and insects, and displaces native species.^[14]

Selected species

Lycium europaeum

Lycium sandwicense

Species include:^[15][16]

Formerly placed here

• Serissa japonica (Thunb.) Thunb. (as L. foetidum L.f. or L. japonicum Thunb.)^[15]

References

Wikimedia Commons has media related to Lycium.

Wikispecies has information related to: Lycium

External links

• Project Lycieae. Amherst College.