Lycium chinense (PROSEA)
Lycium chinense Miller
- Protologue: Gard. dict. ed. 8, n. 5 (1768).
- Family: Solanaceae
- Chromosome number: 2n= 24
- Lycium rhombifolium (Moench) Dippel (1794).
- Chinese boxthorn, Chinese matrimony vine, Chinese wolfberry (En)
- Lyciet (Fr)
- Indonesia: daun koki
- Malaysia: kaukichai, kaukichoy, kei-chi
- Thailand: kaokichai, kaochichai (Bangkok)
- Vietnam: câu khởi, khởi tử, câu kỷ tử.
Origin and geographic distribution
Chinese boxthorn is a native of China and Japan. It is occasionally cultivated and locally naturalized in other areas, e.g. in Hong Kong, Taiwan, Korea, Indo-China, southern Asia (Nepal), South-East Asia (Thailand, Malaysia, Indonesia), and West, Central and South Europe.
Chinese boxthorn is mainly grown for the young shoots and leaves which are used as flavouring and as vegetable. They are added to soups or cooked with pork. Fresh and dried fruits are also used as a flavouring in speciality Chinese dishes.
In traditional medicine, especially in China, Chinese boxthorn is used variously: as an energy restoring tonic (tea from the leaves, wine from the berries), as an antifebrile and antirheumatic tonic (roots), as an aphrodisiac (seeds) and as a cure for a wide range of ailments from skin rashes and eyesight problems to diabetes.
It is also used as an ornamental plant, as a hedge plant (Indo-China, Europe) and as a bonsai plant in Japan.
Production and international trade
Chinese boxthorn is most important in eastern Asia but no statistics are available. In Thailand, Indo-China, Malaysia (Cameron Highlands) and Indonesia (Dieng Plateau) it is grown locally, mainly for consumption by ethnic Chinese.
Per 100 g edible portion the leaves contain: water 90 g, protein 3.9 g, fat 0.6 g, carbohydrates 3.9 g, fibre 1.3 g, β-carotene 4.3 mg, vitamin B10.08 mg, vitamin B20.3 mg, niacin 0.8 mg, vitamin C 8 mg, Ca 142 mg, P 41 mg, Fe 5.2 mg, Na 184 mg and K 498 mg. The energy value is about 150 kJ/100 g.
- A deciduous shrub, 1-2 m tall, branches recurved or pendent, usually provided with a few straight spines.
- Leaves distichous, bright green, with a short petiole; leaf-blade lanceolate to ovate, 1-14 cm × 0.5-6 cm, usually widest below the middle, the lower ones largest, margin entire.
- Flowers solitary or in few-flowered racemes, erect; calyx campanulate, 5-toothed, 3 mm long; corolla funnel-shaped, 5-lobed, 10-15 mm long, tube narrowly cylindrical at the base for 1.5 mm, lobes 5-8 mm long, red-purple with yellowish throat; stamens 5, long-exserted, filaments with dense tuft of hairs at the base; ovary 2-locular, stigma 2-lobed.
- Fruit an ellipsoid berry, about 1 cm × 0.5-0.75 cm, red, many-seeded. Seed 3-4 mm in diameter.
The flowers open in the morning and are cross-pollinated by insects (bees, flies, ants). In Thailand flowering is in June - September, fruiting in August - November. Cultivated plants normally last for about 10 years.
L. chinense is often confused with the closely related L. barbarum L. (synonyms: L. halimifolium Miller, L. vulgare Dunal), which is of similar origin and habit. L. barbarum has elliptical leaves, 2-10 cm × 0.6-3 cm, calyx 4 mm, corolla 9 mm long with tube narrowly cylindrical for 2.5-3 mm and lobes 4 mm long.
Chinese boxthorn is well adapted to a wide range of climatic conditions: annual rainfall may be as low as 300 mm but can be over 2000 mm as well, the temperature range is large. It grows from sea-level up to 2000 m altitude in the tropics. At low altitudes the plant flowers profusely but in the highlands (above 2000 m) it does not flower. It needs a sunny location and tolerates poor soils (sand and rocky soils). The pH range is 5-8.
Chinese boxthorn can be propagated by seed but it is usually vegetatively propagated by hardwood cuttings of 15-20 cm length. Cuttings may be taken at any time and planted in situ at a spacing of 30 cm × 30-50 cm, about 5 cm deep. If planted for fruits, the spacing is usually wider, 40 cm × 120 cm. Plants frequently harvested respond very well to manure and fertilizers. Plants are kept at about 60 cm height.
In Korea, anthracnose caused by Colletotrichum gloeosporioides and C. dematium may cause complete necrosis of the fruits but does not seriously affect leaves and stems.
Harvesting of young shoots may start about two months after planting and be continued at 2-week intervals, but it is better to wait about one year. Soft young shoots of about 30 cm are required. Fruits are harvested when they turn orange-red, and are dried in the sun for 5-7 days. Young shoots and leaves wilt rapidly after harvest; they are sometimes stripped off the stems and kept wet. To be eaten as a vegetable they only need to be cooked for 3-4 minutes.
Genetic resources and breeding
No germplasm collections of Chinese boxthorn are known to exist, but it is likely that some material is available in germplasm collections in China and Japan. In Korea, selection programmes have been carried out, starting from local landraces. Plants with dark green leaves appear to be more drought tolerant than plants with light green leaves.
Chinese boxthorn is an interesting vegetable and medicinal plant. It is easy to cultivate and nutritious. Research should concentrate on selection of high-yielding clones and optimization of cultural practices.
- Larkcom, J., 1991. Oriental vegetables. The complete guide for garden and kitchen. John Murray, London, United Kingdom. pp. 67-69.
- Seo, G.S., Lee, J.Y., Kim, S.Y., Kim, J.K. & Ahn, B.C., 1985. A study on cultural methods of boxthorn (Lycium chinense Mill.). Research Reports of the Rural Development Administration - Crops (Korea R.) 27(2): 218-224.
- Seo, G.S., Lee, J.Y., Kim, S.Y., Kim, J.K. & Han, G.H., 1986. The effects of fertilizer application level and top-dressing method on the yield component and fruit yield of Lycium chinense Mill. Korean Journal of Crop Science (Korea R.) 31(4): 465-469.
- Stearn, W.T., 1972. Lycium L. In: Moore, D.M. (Editor): Solanaceae. Flora Europaea. Vol. 3. Cambridge University Press, United Kingdom. pp. 193-194.
- Y. Paisooksantivatana