Lycium

Lycium is a genus of flowering plants in the nightshade family, Solanaceae. The genus has a disjunct distribution around 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. Common English names for plants of this genus include box-thorn and desert-thorn.
There are about 70 to 80 species. The most common are Lycium barbarum and Lycium chinense, whose fruits (wolfberries or goji berries) are a traditional food crop in China.
Etymology
The generic name Lycium is derived from the Greek word λυκιον (lykion), 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 (Λυκία), the ancient southern Anatolian region in which it grew. The berry is called lycii fructus ("lycium fruit") in old Latin pharmacological texts.
Description
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. Most Lycium have fleshy, red berries with over 10 seeds, but a few American taxa have hard fruits with two seeds.
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.
Uses
Lycium has been known to European herbalists since ancient times, and species were traded from the Far East to Europe by the Romans, 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, as does Pedanius Dioscorides in his P. Dioscoridae pharmacorum simplicium reique medicae.
In his 1753 publication Species Plantarum, Linnaeus describes three Lycium species: L. afrum, L. barbarum, and L. europaeum.
Lycium, particularly L. barbarum, have long been used in traditional Chinese medicine. The leaves and roots of other species of Lycium, such as L. europaeum, when mixed with water, have been used in folk medicine. The fruit of L. barbatum and L. chinense, known as goji berry, is commonly consumed as a dried fruit. The Chinese tonic gou qi zi ("wolfberry fruit") is made of the fruit of any of several Lycium species, and is used as a dietary supplement.
Ecology
Lycium species mostly occur in arid and semi-arid climates, and a few are known from coastal zones in somewhat saline habitat types.
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.
Selected species
Species include:
Lycium acutifolium
Lycium afrum L. – Kraal honey thorn
Lycium ameghinoi
Lycium amoenum
Lycium andersonii – Anderson boxthorn, water-jacket
Lycium arenicola
Lycium australe F.Muell.
Lycium barbarum – Barbary matrimony-vine, Chinese boxthorn, Duke of Argyll's teaplant, goji-berry, Himalayan goji, Tibetan goji
Lycium bosciifolium
Lycium berlandieri Dunal – Berlandier wolfberry
Lycium brevipes – Baja desert-thorn
Lycium californicum – California boxthorn, California desert-thorn
Lycium carolinianum Walter – Carolina desert-thorn, Christmas berry
Lycium chilense Bertero
Lycium chinense – Chinese teaplant, Chinese wolfberry, Chinese boxthorn
Lycium cinereum – Kriedoring
Lycium cooperi – peachthorn, Cooper's wolfberry
Lycium decumbens
Lycium depressum Stocks
Lycium eenii
Lycium europaeum L. – European teatree, European matrimony-vine
Lycium exsertum A.Gray – Arizona desert-thorn, littleleaf wolfberry
Lycium ferocissimum – African boxthorn
Lycium fremontii – Frémont's desert-thorn
Lycium gariepense
Lycium grandicalyx
Lycium hassei – Santa Catalina Island desert-thorn
Lycium horridum
Lycium hirsutum
Lycium intricatum
Lycium macrodon A.Gray – desert wolfberry
Lycium mascarenense A.M. Venter & A.J. Scott (syn. L. tenue var. sieberi)
Lycium nodosum
Lycium oxycarpum Dunal
Lycium pallidum Miers – pale desert-thorn
Lycium parishii – Parish's desert-thorn
Lycium pilifolium
Lycium puberulum – downy desert-thorn
Lycium pumilum
Lycium ruthenicum Murray
Lycium savory D. Jacobson – South America
Lycium sandwicense A.Gray – Ōhelo kai, Hawaii desert-thorn
Lycium schizocalyx
Lycium schweinfurthii
Lycium shawii Roem. & Schult. – Arabian boxthorn
Lycium shockleyi – Shockley's desert-thorn
Lycium sokotranum
Lycium strandveldense
Lycium tenue L.
Lycium tenuispinosum
Lycium tetrandrum
Lycium texanum – Texas wolfberry
Lycium torreyi – Torrey's boxthorn, squawthorn
Lycium tweedianum – tropical desert-thorn
Lycium villosum
Lycium savory D. Jacobson – South America
Formerly placed here
Buchozia japonica (Thunb.) Callm. (as L. foetidum L.f. or L. japonicum Thunb.)
References
External links
Project Lycieae, Amherst College
Solanaceae genera