PROTA homepage Prota 11(1): Medicinal plants/Plantes médicinales 1
Record display


Plumbago auriculata Lam.

Protologue
Encycl. 2: 270 (1786).
Family
Plumbaginaceae
Chromosome number
2n = 14, 16
Synonyms
Plumbago capensis Thunb. (1794).
Vernacular names
Blue plumbago, Cape leadwort, Cape plumbago, skyflower (En). Dentelaire du Cap (Fr). Plumbago azul (Po).
Origin and geographic distribution
Plumbago auriculata is native to South Africa and introduced as an ornamental into most tropical and subtropical countries.
Uses
In southern Africa a decoction of the aerial parts or roots of Plumbago auriculata is taken to treat blackwater fever. A root infusion is taken as an emetic. Root powder is put on warts to make them disappear and is also used as snuff to relieve headache. The powdered, roasted root is rubbed into scarifications over fractures to promote healing, and is rubbed on the body to cure stitch. These treatments are not without danger if large areas are rubbed in, as death by irritation has been recorded. The root extract also acts as a styptic in scrofula.
Plumbago auriculata is grown in gardens throughout the tropics as an ornamental and as a hedge or live fence; in temperate regions it is grown as a pot plant or greenhouse plant. Several cultivars with flowers in different shades of blue exist, as well as a white cultivar. In East Africa the flowers and leaves of Plumbago auriculata are used as a dye for textiles: beige, lemon, yellow (if combined with alum) or gold (if combined with chrome). The sap of the roots is grey-blue, and is used for tattoos. Poultry and sheep readily eat the leaves, but poisoning has been recorded.
Production and international trade
Plumbago auriculata is produced commercially and traded as an ornamental throughout the world.
Properties
All parts of Plumbago auriculata contain the naphthoquinone plumbagin ( 2-methyl juglone), which blisters the skin. Plumbagin possesses a variety of pharmacological activities, i.e. antimicrobial, anticancer, cardiotonic and antifertility actions. It has insecticidal properties as an antifeedant and as a moulting inhibitor. Plumbagin is also a yellow pigment, occurring in a colourless combined form in the plant and is liberated by acid treatment. Plumbago auriculata contains an antifungal protein that inhibits spore germination in Macrophomina phaseolina.
Botany
Perennial herb or small shrub up to 2(–3) m tall; stems erect, trailing or climbing, diffusely branched. Leaves alternate, simple and entire; stipules absent; petiole short with large, amplexicaul auricles at base; blade obovate, elliptical, oblanceolate or spatulate, 2.5–9 cm × 2–6 cm, base long attenuate, apex acute or obtuse, mucronate, pale yellowish-green. Inflorescence a compact terminal spike or raceme, many-flowered, up to 10(–15) cm long; bracts lanceolate, small; peduncle 1–6 cm long, densely hairy. Flowers bisexual, regular, 5-merous; pedicel 0–1 mm long; calyx tubular, 10–12 mm long, 5-ribbed, with sparse short hairs and stalked glands on the upper part; corolla tube cylindrical, 2–3(–4) cm long, lobes broadly obovate, 10–15 mm long, spreading, usually pale blue, sometimes darker blue or white; stamens free, exserted; ovary superior, 1-celled, style filiform, stigma lobes elongated. Fruit an oblong, membranous capsule up to 8 mm long, tapering to the apex, enclosed in the persistent calyx, dehiscent, 1-seeded. Seed oblong, c. 7 mm long, slightly flattened, dark brown or black.
Plumbago comprises about 25 species and occurs almost throughout the world. In tropical Africa about 10 species can be found. Plumbago auriculata flowers all year round, except if the temperature drops below 10°C. The flowers attract large numbers of butterflies.
Ecology
Plumbago auriculata prefers fertile, well-drained, slightly acidic, sandy soils in sunny localities and is drought resistant once established. It grows best in regions with a pronounced dry season. It can withstand some frost; even if killed to the ground, it usually recovers quickly. Plumbago auriculata is salt tolerant.
Management
Plumbago auriculata is propagated by seed, division of older plants, rooted suckers or semi-ripe cuttings. The seeds are sown in seedling trays in a light soil, after which the soil needs to remain moist. The plants are often pruned to form low hedges or borders and are sometimes trained as climbers on arches. Periodic heavy pruning and bright sunlight induce prolific flowering. In temperate regions, Plumbago auriculata can be grown in containers, and kept in a nursery during winter.
Genetic resources and breeding
Plumbago auriculata is widely cultivated and there is no risk of genetic erosion. Several ornamental cultivars are available, e.g. ‘Imperial Blue’, ‘Royal Cape’ with deep blue flowers, ‘Blue Dark’ with dark blue flowers and ‘Alba’ with white flowers.
Prospects
Plumbagin possesses various interesting pharmacological activities, but because of its toxicity the use of Plumbago auriculata in traditional medicine is not without risk. Decoctions of plant parts from Plumbago auriculata in local medicine should therefore be taken with caution.
Major references
• Burkill, H.M., 1997. The useful plants of West Tropical Africa. 2nd Edition. Volume 4, Families M–R. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 969 pp.
• Dyer, R.A., 1963. Plumbaginaceae. In: Dyer, R.A. & Codd, L.E. (Editors). Flora of southern Africa. Volume 26. Botanical Research Institute, Department of Agricultural Technical Services, Pretoria, South Africa. pp. 15–31.
• Hindmarsh, L., 1982. A notebook for Kenyan dyers. National Museum of Kenya, Nairobi, Kenya. 65 pp.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• van Wyk, B.E., van Oudtshoorn, B. & Gericke, N., 1997. Medicinal plants of South Africa. Briza Publications, Pretoria, South Africa. 304 pp.
Other references
• Elgorashi, E.E., Taylor, J.L.S., Maes, A., de Kimpe, N., van Staden, J. & Verschaeve, L., 2002. The use of plants in traditional medicine: potential genotoxic risks. South African Journal of Botany 68(3): 408–410.
• Kubo, I., Uchida, M. & Klocke, J.A., 1983. An insect ecdysis inhibitor from the African medicinal plant, Plumbago capensis (Plumbaginaceae); a naturally occurring chitin synthetase inhibitor. Agricultural and Biological Chemistry 47(4): 911–913.
• Modhumita, G., Thangamani, D., Manisha, T., Yasodha, R. & Gurumurthi, K., 2002. Purification of a 20 KD antifungal protein from Plumbago capensis - a medicinal plant. Journal of Medicinal and Aromatic Plant Sciences 24(1): 16–18.
• Pharkphoom Panichayupakaranant & Supinya Tawtrakul, 2002. Plumbagin production by root cultures of Plumbago rosea. Electronic Journal of Biotechnology 5(3): 228–232.
• Smith, A.R., 2005. Plumbago auriculata. [Internet] Flora of North America. http://www.efloras.org/ florataxon.aspx?flora_id=1&taxon_id=200017524. Accessed 18 august 2005.
• van Steenis, C.G.G.J., 1949. Plumbaginaceae. In: van Steenis, C.G.G.J. (General Editor). Flora Malesiana. Series 1. Vol. 4. Noordhoff-Kolff N.V., Djakarta, Indonesia. pp. 107–112.
• Vickery, A.R., 1983. Plumbaginaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 7, part 1. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 181–184.
• Watt, J.M. & Breyer-Brandwijk, M.G., 1962. The medicinal and poisonous plants of southern and eastern Africa. 2nd Edition. E. and S. Livingstone, London, United Kingdom. 1457 pp.
• Whistler, W.A., 2000. Tropical ornamentals, a guide. Timber Press, Portland, Oregon, United States. 542 pp.
• Wilmot-Dear, C.M., 1976. Plumbaginaceae. In: Polhill, R.M. (Editor). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 12 pp.
Author(s)
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands


Editors
G.H. Schmelzer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
A. Gurib-Fakim
Faculty of Science, University of Mauritius, Réduit, Mauritius
Associate editors
C.H. Bosch
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
M.S.J. Simmonds
Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, United Kingdom
R. Arroo
Leicester School of Pharmacy, Natural Products Research, De Montfort University, The Gateway, Leicester LE1 9BH, United Kingdom
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
General editors
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
Photo editor
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
de Ruijter, A., 2006. Plumbago auriculata Lam. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.
plant habit CopyLeft EcoPort


inflorescences


inflorescence CopyLeft EcoPort


flowers in bud CopyLeft EcoPort


flowers CopyLeft EcoPort


flowers CopyLeft EcoPort