Convolvulus sagittatus (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Vegetable
Medicinal
Forage / feed
Food security

Convolvulus sagittatus Thunb.

distribution in Africa (wild)

Protologue: Prodr. Pl. Cap. 1: 35 (1794).

Family: Convolvulaceae

Chromosome number: × = 15

Vernacular names

• Wild bindweed, wild morning-glory, silverbush (En).

Origin and geographic distribution

Convolvulus sagittatus occurs from Ethiopia and Eritrea south throughout eastern Central Africa and East Africa to South Africa.

Uses

In Burundi a decoction of the leaves is given as enema against diarrhoea. In Zimbabwe a root infusion of Convolvulus sagittatus is given to babies to treat constipation and inflammation of the umbilical cord. A root infusion is given to cattle to drink to treat bloody urine.

Properties

Convolvulus sagittatus contains calystegines, compounds characteristic of most genera of Convolvulaceae.

Description

Very variable perennial herb; stems prostrate or twining, hairy, radiating for up to 1(–2) m from a woody rootstock. Leaves alternate, simple; petiole up to 15 mm long, hairy; blade oblong, triangular-ovate to linear, 2.5–7 cm × 0.5–3 cm, base hastate or sagittate with lobes often bifid or almost truncate, margin obscurely crenate or deeply laciniate, apex acute, more or less hairy, often villous when young. Inflorescence an axillary 1–3(–5)-flowered cyme, hairy; peduncle 2.5–4.5 cm long, slender, often hairy; bracts minute, linear. Flowers bisexual, regular, 5-merous; pedicel c. 0.5 cm long; sepals orbicular, ovate or elliptical, 5–9 mm × 2.5–4 mm, obtuse, the outer longer or narrower particularly in fruit, hairy; corolla funnel-shaped, 8–20(–25) mm long, white, sometimes with pink or purple-red centre or pink with a purple centre; stamens 5, included; ovary superior, 2-celled, style simple, filiform, included, stigmas 2, filiform. Fruit a globose capsule, 6–7 mm long, usually 4-seeded. Seed c. 3.5 mm × c. 2.5 mm, brown or black, nearly glabrous when ripe.

Other botanical information

Convolvulus comprises about 250 species, most of them in temperate and subtropical regions, with only a limited number in the tropics. In tropical Africa about 24 species occur. Numerous varieties have been described in Convolvulus sagittatus, most were later sunk into the species, some are now generally considered separate species, e.g. Convolvulus aschersonii Engl. Several other Convolvulus species are medicinally used in tropical Africa.

Convolvulus arvensis

Convolvulus arvensis L. is a serious deep-rooting weed native of Mediterranean Europe, and has spread to most temperate and dry subtropical regions and several tropical African countries, including Kenya, Mauritius, Madagascar and South Africa. Crushed leaves are applied to wounds to stop bleeding and a root infusion is taken as a laxative. Traditionally the plant is also used to treat skin ulcers, reducing inflammation and swelling. An infusion of the aerial parts is taken against abdominal pain and intestinal worms in children and as a diuretic. A tea made from the flowers is taken as a laxative and also used to treat muscular weakness. A leaf extract is considered immuno-stimulant, and is also taken to treat asthma, jaundice and as an antihaemorrhagic.

Convolvulus farinosus

Convolvulus farinosus L. has a wide distribution in Africa, and the leaves are mainly cooked and eaten as a vegetable. In southern Africa a maceration of the leaves is drunk to treat stomach-ache and the dried stem sap is taken as a drastic purgative. The leaves are considered a good fodder for cattle and the plant is sometimes used as an ornamental. (see main article as a vegetable)

Convolvulus prostratus

Convolvulus prostratus Forssk. (synonym: Convolvulus microphyllus Sieber ex Spreng.) occurs in northern Africa and the Sahel east to western Asia. In tropical Africa no medicinal use has been recorded so far, but in India it is commonly used in Ayurvedic medicine, mainly as an anti-epileptic. A paste of the leaves in milk is taken to treat spermatorrhoea. In Senegal it is not grazed but in Mauritania it is considered good fodder for all cattle.

Growth and development

Convolvulus sagittatus flowers from September to March.

Ecology

Convolvulus sagittatus is a ruderal plant of open woodland and grassland, particularly in disturbed localities, often occurring as a weed, from sea-level up to 2850 m altitude.

Propagation and planting

Convolvulus sagittatus is propagated by seed.

Diseases and pests

Convolvulus sagittatus is a host of the root-knot nematode Meloidogyne javanica, and should be eradicated near crops, including tobacco. The leaves are eaten by the caterpillars of the Convolvulus hawk, Herse convolvuli.

Genetic resources

Convolvulus sagittatus is very common throughout its area of distribution and even considered a weed. It is not threatened by genetic erosion.

Prospects

Too little is known about the pharmacological properties of Convolvulus sagittatus to assess its potential as a medicinal plant. As many other Convolvulaceae have laxative properties, it is likely that the plant will continue to be used for that purpose.

Major references

• Gelfand, M., Mavi, S., Drummond, R.B. & Ndemera, B., 1985. The traditional medical practitioner in Zimbabwe: his principles of practice and pharmacopoeia. Mambo Press, Gweru, Zimbabwe. 411 pp.
• Gonçalves, M.L., 1987. Convolvulaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 8, part 1. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 9–129.
• Meyer, J.C. & van Wijk, R.J., 1989. Susceptibility of rotation crops and weeds in tobacco fields to Meloidogyne species and host races. Phytophylactica 21(2): 205–207.
• Sebsebe Demissew, 1999. A synopsis of the genus Convolvulus (Convolvulaceae) in Ethiopia and Eritrea. Kew Bulletin 54(1): 63–79.

Other references

• Burkill, H.M., 1985. The useful plants of West Tropical Africa. 2nd Edition. Volume 1, Families A–D. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 960 pp.
• Deroin, T., 2001. Convolvulaceae. Flore de Madagascar et des Comores, familles 133 bis et 171. Muséum National d’Histoire Naturelle, Paris, France. pp. 11–287.
• Gupta, A.K., Tandon, N. & Sharma, M. (Editors), 2005. Quality standards of Indian medicinal plants. Volume 2. Indian Council of Medical Research, New Delhi, India. 301 pp.
• Kapadia, N.S., Acharya, N.S., Suhagia, B.N. & Shah, M.B., 2005. A pharmacognostical study on Convolvulus prostratus Forssk. Journal of Natural Remedies 5(2): 108–114.
• Manbir, K. & Kalia, A.N., 2012. Convolvulus arvensis - a useful weed. International Journal of Pharmacy and Pharmaceutical Sciences 4(1): 38–40.
• Polygenis-Bigendako, M.J. & Lejoly, J., 1989. Plantes employées dans le traitement des diarrhées en médecine traditionnelle au Burundi occidental. Bulletin de la Société Royale de Botanique de Belgique 122(1): 87–97.
• Schimming, T., Jenett-Siems, K., Mann, P., Tofern-Reblin, B., Milson, J., Johnson, R.W., Deroin, T., Austin, D.F. & Eich, E., 2006. Calystegines as chemotaxonomic markers in the Convolvulaceae. Phytochemistry 66(4): 469–480.
• 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.

Author(s)

• G.H. Schmelzer, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Schmelzer, G.H., 2013. Convolvulus sagittatus Thunb. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(2): Medicinal plants/Plantes médicinales 2. PROTA, Wageningen, Netherlands. Accessed 23 December 2024.

• See this page on the Prota4U database.