Arctium lappa (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Arctium lappa L.

Protologue: Sp. pl. 2: 816 (1753).

Family: Compositae

Chromosome number: 2n= 36

Synonyms

• Lappa vulgaris Hill (1762),
• Lappa major Gaertner (1791).

Vernacular names

• Great burdock, edible burdock, beggar's buttons (En)
• Bardane, gouteron, oreille de géant (Fr)
• Japan: (yama-)gobo
• Indonesia: gobo
• Vietnam: ngưu bàng

Distribution

A. lappa is indigenous from Europe to China and Japan, and has been introduced into North America. It is cultivated mainly in Japan, but also in China, Vietnam, the Philippines, Indonesia, Hawaii, New Zealand and Europe.

Uses

In China, Vietnam, India, and Europe A. lappa is well known as a medicinal plant. It possesses heart stimulant, stomachic, anodyne, anti-scorbutic, antipyretic, laxative, diaphoretic, depurative, anti-inflammatory and diuretic properties. It is used for a great variety of diseases including furunculosis, suppurating abscesses, swellings, scrofulous gout, psoriasis, acne and prurigo, throat infections, pneumonia, chronic gastritis, scarlet fever, measles, small pox, rheumatism, vertigo, cancer, syphilis, and baldness. The tincture from the fresh roots is used to treat pulmonary catarrh, rheumatism and gout. The whole plant, or only the fruit, is employed as an ointment or liniment for burns, ulcers and other cutaneous diseases. However, cases of contact dermatitis caused by A. lappa root plasters, applied for anti-inflammatory purposes, are known. In East Asia, the fruits are used as a cure against bites of poisonous insects and snakes, and against flatulence. They are exported to Indo-China and sold as a depurative, and are found in Chinese pharmacies in Peninsular Malaysia. The root contains an essential oil.

A decoction of the fruit of A. lappa and Trichosanthes kirilowii Maxim. is a cure for subclinical mastitis in calves of mastitis-positive cows. In India the plant is also used to treat scurf or skin diseases of animals and to prevent hair loss in humans and animals.

In Japan, A. lappa, called "(yama-)gobo", is a popular vegetable. The slightly fibrous mucilaginous roots have a sweetish taste and are consumed raw or cooked. The peeled tender petioles and young floral stalks are eaten less widely. North American Indians eat the young leaves as well as the fresh or dried roots. In Europe cows eat the leaves readily, but they may give milk a bitter flavour if eaten in large quantities. In China, Vietnam and Europe it is a weed of disturbed, neglected places.

Production and international trade

No information is available on the production of A. lappa for medicinal purposes. Most A. lappa is cultivated in Japan for its edible roots. In Taiwan, Vietnam and New Zealand, A. lappa is produced for the Japanese market and for local Japanese people. The annual production of A. lappa roots for consumption in Taiwan rose from 16 t in 1990 to 25-30 t in 1993, while the cultivated area rose from 265 ha to 898 ha. In Japan, production in the early 1990s was estimated at 180 000 t/year from 14 000 ha, of which 140 000 t were purchased for consumption, 10 000 t were used for the chilled cut vegetable trade, 500 t were processed for dehydration, 200 t were frozen, and the remainder was used as stock feed.

Properties

A. lappa has been investigated phytochemically quite well. As in many other Compositae, the roots of A. lappa contain 45-60% inulin, a fructose based polysaccharide. They also contain a volatile oil (0.06-0.18%) consisting of more than 60 compounds, e.g. phenylacetaldehyde, sesquiterpenes such as costusacid and costuslactone, several sulphur containing acetylenes and derivates, arctinone A and B, arctinone A acetate, arctinol A and B, arctinal, arctic acid, and lappaphen-A and -B. Non-sulphur containing acetylenes (0.001-0.002%) are also present, with (S)-12,13-epoxy-2,4,6,8,10-tridecapentayne, 1,3,11-tridecatriene-5,7,9-triyne and 1-tridecen-3,5,7,9,11-pentayne as the major components. The fresh roots contain up to 3.6% polyphenolics, together with chlorogenic-, caffeic- and caffeoylquinic-acid derivates. The unsaturated bitter sesquiterpene lactone arctiopicrine is present in all plant parts. Other constituents of the herb are the sesquiterpenes arctiol (= 8-hydroxyeudesmol), β-eudesmol, fukinone, the sesquiterpene lactones onopordopicrine and fukinanolide, and triterpenes such as α-amyrin, taraxasterolacetate and lupeolester.

Among the isolated compounds mentioned, the polyacetylenes (S)-12,13-epoxy-2,4,6,8,10-tridecapentayne and 1-tridecen-3,5,7,9,11-pentayne show good antibacterial and antifungal activity. The sesquiterpene lactone arctiopicrine is also an antibacterial principle, active against both gram positive and gram negative bacteria, although it is extremely sensitive to oxidation. Of the anti-oxidative quinic acid derivatives from the root, (1,3,5)-O-tricaffeoyl-4-O-succinylquinic acid showed the highest anti-oxidant activity.

Several tests were performed to evaluate the medicinal properties of A. lappa extracts. Subcutaneous administration of a crude extract of the roots significantly decreased carrageenan-induced rat paw oedema. Simultaneous administration of the extract with CC1₄, reduced CC1₄-induced acute liver damage. The IC₅₀ of the extract on superoxide and hydroxyl radical scavenger activity was 2.1 mg/ml and 11.8 mg/ml, respectively. These results indicate that A. lappa possesses free radical scavenging activity, likely to cause the inhibitory effects on oedemas and hepatotoxicity. The plant was also tested in prevention and treatment of kidney stone formation using female Wistar rats. An evaluation of the main urolithiasis risk factors (citraturia, calciuria, phosphaturia, pH and diuresis) showed that the beneficial effects can be mainly attributed to some disinfectant action. A. lappa extract causes a sharp, long-lasting reduction of the blood-sugar level of rats, with an increase in carbohydrate tolerance, especially for diabetics. In a test for treatment of diabetes in normal and streptozotocin induced diabetic mice, however, A. lappa did not affect the parameters of glucose homeostasis examined in normal mice, but worsened the diabetic condition in the other mice. Crude extracts were tested in several cell lines for anti-HIV activity and cytotoxicity, but inhibition of HIV-1 replication could not be shown in all tests. The hot water extract showed RNA reverse transcriptase inhibiting activities. Methanol extracts were subjected to a screening test for larvicidal and antifeeding activity against two species of lepidopteran larvae, diamondback moth (Plutella xylostella) and tobacco cutworm (Spodoptera litura), using a leaf-dipping method. At 5000 ppm strong antifeeding activity against both larvae was observed.

The fruits of A. lappa are called "bardanae fructus". They are known to contain a broad spectrum of lignans. Arctiin, arctigenin and matairesinol are lignans containing 2 phenylpropane residues. Lappaol A-E contain 3 residues, and the dilignans lappaol F-H, neoarctin A and B, and diarctigenin (= bis-5',5'-arctigenin) 4 residues. Other isolated lignans mentioned in literature are arctilignans A-E and trachelogenin, and other important compounds are chlorogenic acid and daucesterol (a phytosterol). Pharmacological activities attributed to these compounds include differentiation-induction of M1 (mouse myeloid leukaemia) cells by lignans and dilignans. Arctigenin was the most effective of all, inducing differentiation at 0.5 μM; in general, phagocytic activity of differentiated M1 cells was higher of lignans than that of dilignans. Trachelogenin produced a long-lasting anti-hypertensive effect through Ca²⁺ antagonist activity in rats, and arctiin and arctigenin showed strong cytotoxicity against HepG2 cells, but little toxicity against Chang liver cells. Chlorogenic acid did not affect the viability of these cells. Furthermore, the cytotoxicity of arctigenin against Chang liver cells, but not for HepG2 cells, was markedly potentiated by treatment with L-butathione-(S,R)-sulphoximine (BSO, a glutathione synthesis inhibitor). Extracts of A. lappa fruits were also tested for their inhibitory effect on the binding of platelet activating factor (PAF) to rabbit platelets, and were found to be significantly active. This activity is attributed to the presence of lignans.

A desmutagenic factor was isolated from A. lappa, which reduced the activity of a series of well known mutagens, including nitrobenzene derivatives (NDAB), ethium bromide, 2-aminoanthracene, Trp-P-1, and Trp-P-2. It is resistant to heat and proteolytic enzymes and sensitive to treatment with MnCl₂. The factor was shown to be a complex polymer with molecular weight of around 30 000, possibly a lignin-like compound with 10% sugar content. In Canada the herbal drug "Essiac", composed of A. lappa, Rheum palmatum L., Rumex acetosella L. and Ulmus fulva Michx., has been used for over 70 years in cancer therapies. There is some preliminary clinical evidence that "Essiac" may be effective in treating breast cancer.

Rats first fed on a diet of A. lappa fibres with or without the inclusion of 8% mineral oil in a fat-free diet, showed a severe growth retardation without addition of the fibres. The A. lappa fibres, as well as cotton cellulose powder, inhibit mineral oil absorption from the intestinal lumen. In a test with the food colours amaranth, erythrosine, tartrazine, brilliant blue, new coccine and sunset yellow, all food colours caused severe growth retardation of weanling rats. When 5% fibre from the roots of A. lappa was added, growth was not retarded by any colour except for erythrosine.

Adulterations and substitutes

Sarsaparilla (Smilax sp.) is an important anti-inflammatory and a remedy for venereal affections, and could be a substitute for A. lappa. Asparagus roots are eaten as a substitute for A. lappa roots.

Observations

• A biennial, robust and much branched herb, 40-100(-210) cm tall when flowering; taproot up to 1.5 m long in the second year, brownish to weak yellowish-orange, but for consumption a length of 60-70 cm and a diameter of 2.5-3 cm are preferred.
• Basal leaves arranged in a rosette, cauline leaves alternate, simple, heart-shaped, up to 40-50 cm × 15-20 cm, margin irregularly undulate, upper surface glabrous, underneath covered with white hairs; petioles (5-)20-30 cm long; stipules absent.
• Inflorescence a head, one or more together in a lax terminal or axillary corymbose cyme; peduncle 2.5-20 cm long, involucre hemispherical, involucral bracts herbaceous, bright green, margin in the lower half membranaceous, with few to many glandular hairs, the upper part slightly recurved, straight or (slightly) hooked, the head thus becoming a burr, heads rounded, 3-4.5 cm × 2-3 cm.
• Flowers all tubular, more than 40, lobes 5, corolla 9.5-14.5 mm long, mostly purplish; stamens 5; ovary inferior.
• Fruit an obovoid achene, 6-8 mm × 2.4-3.2 mm, angular, chestnut-brown.
• Seedling with epigeal germination; hypocotyl wrinkled and white, cotyledons large and rounded; epicotyl absent; first leaves alternate.

Growth and development

In the first year, the average number of leaves of A. lappa is 20, with a leaf dry weight of about 60 g/plant. The taproot shows xylem thickening. In some cultivars a pith cavity starts developing during the 4th month after sowing and becomes quite large at harvest time, at the end of the 5th month after sowing. Early cultivars for root production mature in 120 days, late cultivars in 200 days.

Other botanical information

Arctium belongs to the tribe Cardueae, and comprises 11 species (including part of the species formerly belonging to Cousinia) and 6 hybrids. A. minus (Hill) Bernh. (lesser burdock) is closely related to A. lappa, but differs from the latter by having hollow petioles and smaller flower heads. The natural hybrid between A. lappa and A. minus, A. × nothum (Ruhm) Weiss, occurs occasionally throughout Western Europe, often among its parents. Its achenes are often abortive. A cultivar trial of A. lappa showed little difference among cultivars, but "Ooura" showed a higher yield for all plant parts, and had a conspicuous pith cavity formation of the root.

Ecology

A. lappa is found in ruderal, neglected locations, along roads and in fields as a weed, along streams and ditches, forest edges and marshlands. It tolerates a wide range of climates, and grows from sea-level up to 3200 m altitude. It grows in light to heavy, dry to moist soils, in full sunshine or in the shade.

Propagation and planting

A. lappa is propagated by seed. Seeds germinate at 10-36°C, the optimum temperature being 21-30°C. Germination rate is around 90%. The optimum sowing depth is 2 cm, deeper than 4 cm reduces germination rate considerably. The seeds germinate 3-4 days after sowing. In New Zealand a plant density of 20 plants/m² is considered optimal for root production.

Husbandry

In Japan, A. lappa is cultivated on a large scale and many operations are mechanized. Phosphorous fertilizer increases shoot dry weight and decreases mycorrhizal infection rate. Leaf N-uptake of A. lappa decreases when leaves begin to wither after attaining maximum growth in the 4th month. Root N-uptake increases after the leaves wither completely. Root hypertrophy, dry matter content and inulin content decreases when fertilizer application is further increased. Continuous cropping of A. lappa causes inhibition of germination and damping-off at seedling stage, while in the growth stage leaf width, plant height and root length become abnormal, and the roots are deformed and develop necrotic spots. Application of phenolic acids may improve crop growth, although plant growth is less than the first cropping.

In Taiwan A. lappa is mainly grown in the winter season and all the necessary fertilizer is applied in a single dose during land preparation.

Diseases and pests

Several important diseases of A. lappa in Japan are caused by: Aspergillus ochraceus, Fusarium oxysporum f. arctii, Erysiphe cichoracearum, Pythium irregulare, Scepticus uniformis, S. griseus, Sclerotinia sclerotiorum, and Sphaerotheca fuliginea. A. lappa is a host for the following viruses: burdock mottle virus (also infecting Chenopodium murale L., C. quinoa L. and Nicotiana rustica L.), burdock mosaic virus, burdock yellow virus (a closterovirus), tobacco ringspot virus (TobRV), burdock stunt disease, and tomato spotted wilt tospovirus. Important insect pests found on A. lappa in Japan are: Tebenna issikii, Pantomorus cervinus (which feeds on the roots), and thrips.

Harvesting

The roots are dug up the end of the first year's growth, when they are about 60-80 cm long and 2.5 cm in diameter, and the root dry weight is 70-80 g/plant.

Yield

In New Zealand, yields of A. lappa roots are as high as 39 t/ha under experimental conditions. This is considerably higher than yields obtained in Japan, which are 13 t/ha. Under experimental conditions in Germany, a 1-year old crop yielded 6 t of roots per hectare, giving 450 kg of inulin, and 7.5 t of dry stems, yielding 3 t of good quality cellulose.

Handling after harvest

In Taiwan the roots of A. lappa are washed and carefully dried, and then stored for 1-2 months at 0-5°C for the transformation of starch to saccharide. After 2 months of storage the content of saccharide increases from 50% to 75%, while that of starch reduces from 35% to 4%. The roots are then cut into 1.7 mm thick slices, which are dried for 15 minutes at 160°C. The farmers produce A. lappa under a guaranteed price-contract with dealers.

Genetic resources and breeding

A. lappa is widely distributed and will not easily become endangered. Small germplasm collections are known to exist in Brazil, China, Germany, Poland and the United Kingdom. Breeding programmes on root production are being carried out in Japan.

Prospects

Compounds from A. lappa show several interesting pharmacological activities, including antimicrobial, cytotoxic and anti-oxidant effects, which seem worthwhile for further research. Furthermore, the leaves of A. lappa are one of the best sources of pectinesterase and polygalacturonase for commercial clearing of fruit-juices. Air-dried, the enzymes retain a high activity for several months.

Literature

• Chen, H.B. & Chen, Y.W., 1995. Current status and prospect of great burdock industry in Taiwan. In: Kuo, J.Y. (Editor): Proceedings of a symposium on the improvement of vegetable industry in Taiwan held at Taichung District Agricultural Improvement Station, 25-26 May 1994. Special Publication Taichung District Agricultural Improvement Station 37. pp. 291-302. (in Chines)
• Douglas, M.H., Burgmans, J.L., Burton, L.C. & Smallfield, B.M., 1992. The production of burdock (Arctium lappa L.) root in New Zealand - a preliminary study of a new vegetable. Proceedings of the Annual Conference of the Agronomy Society of New Zealand 22: 67-70.
• Duistermaat, H., 1996. Monograph of Arctium L. (Asteraceae). Generic delimitation (including Cousinia Cass. p.p.), revision of the species, pollen morphology, and hybrids. Gorteria Supplement 3: 1-143.
• Inouye, T. & Mitsuhata, K., 1971. Viruses in burdock, Arctium lappa L. 2. Studies on the viruses of plants in Compositae in Japan. Nogaku Kenkyu 54(1): 1-14. (in Japanese)
• Morita, K., Kada, T. & Namiki, M., 1984. A desmutagenic factor isolated from burdock (Arctium lappa Linn√©). Mutation Research 129(1): 25-31.
• Moritani, S., Nomura, M., Takeda, Y. & Miyamoto, K., 1996. Cytotoxic components of Bardanae Fructus (Goboshi). Biological and Pharmaceutical Bulletin 19(11): 1515-1517.

Other selected sources

• [7] Abiko, K., 1978. Studies on the specialization of parasitism of Sphaerotheca fuliginea (Schlecht.) Pollacci I. Powdery mildew fungi parasitic on cucurbits, eggplant, edible burdock and Japanese butterbur. Annals of the Phytopathological Society of Japan 44(5): 612—618.
• [97] Bautista, R., Mau, R.F.L., Cho, J.J., Custer, D. & Kuo, C.G., 1996. Thrips, tospovirus, and host-plant associations in a Hawaiian farm ecosystem: prospects for reducing disease losses. International Symposium on Tospoviruses and Thrips of Floral and Vegetable Crops, Taiwan Agricultural Research Institute, Taichung, Taiwan. Acta Horticulturae 431: 477—482.
• [9]Bailey, L.H., 1975. Manual of cultivated plants. 15th printing of 1951 edition (1st edition, 1924). Macmillan, New York, United States. 1116 pp.
• [120] Blaschek, W., Hänsel, R., Keller, K., Reichling, J., Rimpler, H. & Schneider, G. (Editors), 1998. Hagers Handbuch der Pharmazeutischen Praxis. Folgeband 2: Drogen A—K [Hagers handbook of the practice of pharmacology. Suppl. 2: drugs A—K]. 5th Edition. Springer Verlag, Berlin, Germany. 909 pp.
• [203] Collins, R.A., Ng, T.B., Fong, W.P., Wau, C.C. & Yeung, H.W., 1997. A comparison of human immunodeficiency virus type 1 inhibition by partially purified aqueous extracts of Chinese medicinal herbs. Life Science 60(23): 345—351.
• [215] Council of Scientific and Industrial Research, 1948—1976. The wealth of India: a dictionary of Indian raw materials & industrial products. 11 volumes. Publications and Information Directorate, New Delhi, India.
• [361] Grases, F., Melero, G., Costa-Bauza, A., Prieto, R. & March, J.G., 1994. Urolithiasis and phytoterapy. International Urology and Nephrology 26(5): 507—511.
• [382] Hamada, Y., Aoki, H., Miyashita, H., Yamaguchi, Y. & Tanabe, H., 1984. Studies on the mechanization of the culture of edible burdock (Arctium lappa L.) II. Measurement of pulling resistance for harvesting and a field trial of a test digger. Research Bulletin of the Aichi Ken Agricultural Research Center 16: 138—146. (in Japanese)
• [383] Hamada, Y., Aoki, H., Yamaguchi, Y. & Miyashita, 1983. Studies on the mechanization of edible burdock (Arctium lappa L.) culture. I. Mechanical sowing of edible burdock. Research Bulletin of the Aichi Ken Agricultural Research Center 15: 178—186. (in Japanese)
• [397] Hayashi, M., 1997. Effects of phenolic acids on the continuous cropping injury of edible burdock (Arctium lappa). Japanese Journal of Soil Science and Plant Nutrition 68(2): 123—130. (in Japanese)
• [43]Herklots, G.A.C., 1972. Vegetables in South-East Asia. George Allen & Unwin, London, United Kingdom. 525 pp.
• [445] Horie, Y., Yamazaki, M. & Mitake, S., 1982. On the toxogenic fungi contaminating herbal drugs. II. Floral and mycotoxicological survey of fungi in herbal drugs as raw materials in pharmaceutical industries. Transactions of the Mycological Society of Japan 23(4): 435—447. (in Japanese)
• [46]Hotta, M., Ogata, K., Nitta, A., Hosikawa, K., Yanagi, M. & Yamazaki, K. (Editors), 1989. Sekai yuhyou-shokubutu jiten [Useful plants of the world]. Heibonsha, Tokyo, Japan. 1499 pp.
• [460] Ichikawa, K., Kinoshita, T., Nishibe, S. & Sankawa, U., 1986. The Ca2+ antagonist activity of lignans. Chemical and Pharmaceutical Bulletin 34(8): 3514—3517.
• [468] Inouye, T., 1973. Host range and electron microscopy of burdock mottle virus, a rod-shaped virus from Arctium lappa L. IV. Studies on the viruses of plants in Compositae in Japan. Berichte des Ohara Instituts für Landwirtschaftliche Biologie Okayama Universität 15(4): 207—218.
• [475] Iwakami, S., Wu, J.B., Ebizuka, Y. & Sankawa, U., 1992. Platelet activating factor (PAF) antagonists contained in medicinal plants: lignans and sesquiterpenes. Chemical and Pharmaceutical Bulletin 40(5): 1196—1198.
• [476] Iziro, Y., 1986. Studies on the pith cavity of edible burdock (Arctium lappa L.), 1: The growth of each part of edible burdock and the occurrence of the pith cavity in the main root. Bulletin of the College of Agriculture Utsunomiya University 13(1): 111—121. (in Japanese)
• [497] Kaegi, E., 1998. Unconventional therapies for cancer: 1. Essiac. Canadian Medical Association Journal 158: 897—902.
• [576] Kwon, H.W., Ahn, Y.J., Kweon, J.H., Lee, S.G. & Byun, B.H., 1994. Larvicidal and antifeeding activities of oriental medicinal plant extracts against Plutella xylostella and Spodoptera litura. Agricultural Chemistry and Biotechnology 37(6): 503—508.
• [612] Lin, C.C., Lu, J.M., Yang, J.J., Chuang, S.C. & Ujiie, T., 1996. Anti-inflammatory and radical scavenge effects of Arctium lappa. American Journal of Chinese Medicine 24(2): 127—137.
• [647] Mansfeld, R., 1986. Verzeichnis landwirtschaftlicher und gärtnerischer Kulturpflanzen (ohne Zierpflanzen) [Register of agricultural and horticultural plants in cultivation (without ornamentals)]. Schultze-Motel, J. et al. (Editors). 2nd Edition. 4 volumes. Springer Verlag, Berlin, Germany. 1998 pp.
• [650] Maruta, Y., Kawabata, J. & Niki, R., 1995. Antioxidative caffeoylquinic acid derivates in the roots of burdock (Arctium lappa L.). Journal of Agricultural and Food Chemistry 43(10): 2592—2595.
• [682] Moerman, D.E., 1998. Native American ethnobotany. Timber Press Portland, Oregon, United States. 927 pp.
• [695] Morita, T., Ebihara, K. & Kiriyama, S., 1993. Dietary fiber and fat-derivates prevent mineral oil toxicity in rats by the same mechanism. The Journal of Nutrition 123(9): 1575—1585.
• [716] Nakano, M. & Inouye, T., 1980. Burdock yellow virus, a closterovirus from Arctium lappa L. Annals of the Phytopathological Society of Japan 46(1): 7—14.
• [739] Nguyen Van Duong, 1993. Medicinal plants of Vietnam, Cambodia and Laos. Mekong Printing, Santa Ana, California, United States. 528 pp.
• [742] Nishida, T., 1998a. Germination and growth properties of edible burdock. Bulletin of the Hokkaido Prefectural Agricultural Experiment Stations 74: 43—51. (in Japanese)
• [743] Nishida, T., 1998b. Nutritive properties and optimum nitrogen fertilizer amount of edible burdock. Bulletin of the Hokkaido Prefectural Agricultural Experiment Stations 74: 53—61. (in Japanese)
• [786] Perry, L.M., 1980. Medicinal plants of East and Southeast Asia. Attributed properties and uses. MIT Press, Cambridge, Massachusetts, United States & London, United Kingdom. 620 pp.
• [845] Rodriguez, P., Blanco, J., Juste, S., Garces, M., Perez, R., Alonso, L. & Marcos, M., 1995. Allergic contact dermatitis due to burdock (Arctium lappa). Contact Dermatitis 33(2): 134—135.
• [870] Sasai, K., 1991. Effect of phosphate application on infection of vesicular-arbuscular mycorrhizal fungi in some horticultural crops. Scientific Reports of the Miyagi Agricultural College 39: 1—9. (in Japanese)
• [80]Shinohara, S. (Editor), 1984–1989. Vegetable seed production technology of Japan. 2 volumes. Shinohara's Authorized Agricultural Consulting Engineer Office, Tokyo, Japan. Vol. 1 (1984) 432 pp., Vol. 2 (1989) 317 pp.
• [914] Siemonsma, J.S. & Kasem Piluek (Editors), 1993. Plant Resources of South-East Asia No 8. Vegetables. Pudoc Scientific Publishers, Wageningen, the Netherlands. 412 pp.
• [975] Swanston-Flatt, S.K., Day, C., Flatt, P.R., Gould, B.J. & Bailey, C.J., 1989. Glycaemic effects of traditional European plant treatments for diabetes. Studies in normal and streptozotocin diabetic mice. Diabetes Research 10(2): 69—73.
• [982] Takeda, H., Tsujika, J., Ebihara, K. & Kiriyama, S., 1981. Decreased protein utilization in amaranth toxicity and its amelioration by the concurrent feeding of dietary fiber in rats. Nutrition Reports International 24(3): 481—497.
• [1060] Wei, C., Po, T., Xiang, Z. & Yong, L., 1983. Viroid-like RNAs associated with burdock stunt disease of Arctium tomentosum and Arctium lappa. Journal of General Virology 64: 409—414.
• [1064] Wheeler, B.E.J., Cook, R.T.A., Fagan, H.J., Chandarasrivongs, C., Khan, A.N. & Achavasmit, P., 1973. Erysiphe cichoracearum on Arctium lappa: cleistocarp dehiscence, ascospore germination, and infection of cucumber by ascospores and conidia. Transactions of the British Mycological Society 60(2): 177—186.
• [97]Yamaguchi, M., 1983. World vegetables: principles, production and nutritive values. Avi Publishing Company, Westport, Connecticut, United States. 415 pp.
• [1103] Yao, X.J., Wainberg, M.A. & Parniak, M.A., 1992. Mechanism of inhibition of HIV-1 infection in vitro by purified extract of Prunella vulgaris. Virology 187(1): 56—62.
• [1129] Zhou, J.T., Lei, Y., Wu, D.F., Hou, H.S. & Huang, Y.F., 1984. Effects of Chinese materia medica through ion-conduction on subclinical mastitis of cows. Journal of Fujian Agricultural College 13(3): 231—236. (in Chinese)

Authors

• G.H. Schmelzer & S.F.A.J. Horsten