PROTA homepage Prota 11(1): Medicinal plants/Plantes médicinales 1
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Strophanthus preussii Engl. & Pax

Protologue
Bot. Jahrb. Syst. 15: 369 (1892).
Family
Apocynaceae
Vernacular names
Spider tresses, poison arrow vine (En).
Origin and geographic distribution
Strophanthus preussii occurs in the forest area of West and Central Africa, from Sierra Leone east to the Central African Republic, and extending to Uganda and northern Tanzania, and south to southern DR Congo and Angola.
Uses
In Côte d’Ivoire the latex or the young leaves crushed in water are applied to treat gonorrhoea. A leaf decoction is taken to treat post-partum pain in the Central African Republic. In DR Congo the latex is put on sores and wounds to promote healing. The latex or seeds are used in arrow poison mixtures in Liberia and DR Congo, but because they are less toxic than those of Strophanthus gratus (Wall. & Hook.) Baill. and Strophanthus hispidus DC., they are of second choice. The stems are used to make bows in southern Nigeria. The latex has been used for coagulating Funtumia latex in Ghana. In the Central African Republic the fibre is used to make fishing lines, nets and ropes. In Gabon the young leaves are said to be cooked and eaten as a vegetable. Strophanthus preussii is sold as an ornamental in the United States, because of its strikingly beautiful flowers with very long corolla tails. The flowering branches are sometimes used as cut-flower.
Properties
The seeds of Strophanthus preussii are not rich in cardiac glycosides (cardenolides); they contain 0.5–1% glycosides. The glycosides are mainly based on the aglycone periplogenin, with periplocin, periplocymarin and emicymarin as main components. Small amounts of glycosides based on the aglycone strophanthidin are also present. The toxicity of the strongly cardio-active periplocin, periplocymarin and emicymarin is only slightly less than that of ouabain, a well-known compound found in other Strophanthus spp., especially Strophanthus gratus.
Description
Evergreen liana up to 12 m long or less often a shrub up to 5 m tall, with clear or white exudate, stem up to 2.5 cm in diameter; branches with few to many lenticels, reddish to purple-brown. Leaves decussately opposite, simple and entire; stipules absent; petiole 2–9(–14) mm long; blade ovate or elliptical to slightly obovate, 2–18.5 cm × 1.5–7.5 cm, base cuneate, rounded to rarely slightly cordate, apex acuminate, papery or thinly leathery, glabrous. Inflorescence a terminal dichasial cyme, on long or short branches or in the forks, lax, few- to many-flowered; peduncle 0–24 (–35) mm long; bracts ovate or orbicular to obovate, 4–20 mm long, sometimes deciduous. Flowers bisexual, regular, 5-merous, fragrant; pedicel 4–25 mm long; sepals free, unequal, ovate to narrowly ovate or linear, 4–25 mm long, acute or obtuse; corolla tube 12–26 mm long, widening at 40–66% of its length into a cup-shaped upper part, at the mouth 7–17 mm wide, minutely hairy except outside near the base, white turning reddish orange via yellow, outside suffused with pink at the base and with red near the apex, inside red-spotted and -streaked, corona lobes tongue-shaped, 1–2.5 mm long, rounded, fleshy, minutely hairy, yellow turning orange, pink- or purple-streaked, corolla lobes ovate, gradually narrowing into a narrow, spreading tail, lobes including the tail 25–75 mm long, minutely hairy except for the apex, white and with 3 pink lines, the white turning yellow; stamens inserted at 8–14.5 mm from the base of the corolla tube, exserted or included; ovary half-inferior, 2-celled, style 7.5–13.5 mm long, ending in a ringlike pistil head surrounding the stigma. Fruit consisting of 2 ellipsoid follicles (13–)15–29 cm × 1–3 cm, tapering into a narrow obtuse apex, or with a small or large knob, 2-valved, divergent at 160–190°, wall rather thick and hard, slightly or conspicuously grooved, glabrous, with many elongated lenticels, many-seeded. Seeds spindle-shaped, 12–20 mm × 2–3.5 mm, densely hairy, at apex with a long beak up to 6 cm long, glabrous for 3–8 mm in basal part and in upper part with long hairs up to 10 cm long.
Other botanical information
Strophanthus comprises 38 species, of which 30 occur in continental Africa, 1 in Madagascar and 7 in Asia, from India to South-East Asia. Strophanthus preussii is related to Strophanthus barteri Franch. and Strophanthus gracilis K.Schum. & Pax. Strophanthus barteri is a slender liana from the forest area of West Africa and western Central Africa. In Ghana the stem bark in decoction is taken to treat diarrhoea, a use supported by pharmacological tests. In Côte d’Ivoire it is becoming rare because of overharvesting. Strophanthus gracilis occurs from Nigeria to Gabon, in coastal and riverine forest. The seeds and latex are used in arrow and fish poisons. It has a high content of cardiac glycosides.
Growth and development
Strophanthus preussii flowers in the dry season and the first part of the long rainy season; fruit ripens in the dry season.
Ecology
Strophanthus preussii occurs in primary and secondary moist forest, gallery forest, forest margins and clearings, from sea-level up to 1400 m altitude.
Propagation and planting
Strophanthus preussii can be propagated by seed or by soft wood cuttings.
Management
Strophanthus preussii grows to a shrub 1–2 m tall when potted. It needs to be kept at a minimum temperature of 25°C, in half-shade. It should be planted in fertile, humus-rich, well-drained soil, and regularly watered. A slightly alkaline soil is preferred. Strophanthus preussii may drop its leaves in the cool, dry season.
Harvesting
The pods need to dry on the plant before they are harvested and opened to get the seeds.
Genetic resources
Because of its wide distribution and its habitat range Strophanthus preussii is not threatened by genetic erosion.
Prospects
Strophanthus preussii will remain of local importance only, as it contains only low levels of glycosides. As an ornamental it is promising.
Major references
• Beentje, H.J., 1982. A monograph on Strophanthus DC. (Apocynaceae). Mededelingen Landbouwhogeschool Wageningen 82–4. Wageningen, Netherlands. 191 pp.
• 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.
• Neuwinger, H.D., 1996. African ethnobotany: poisons and drugs. Chapman & Hall, London, United Kingdom. 941 pp.
Other references
• Burkill, H.M., 2000. The useful plants of West Tropical Africa. 2nd Edition. Volume 5, Families S–Z, Addenda. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 686 pp.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• Quarm, I., 1989. Antidiarhoeal properties and some preliminary chemical investigation on the stem of Strophanthus barteri. B. Pharm. Degree thesis, Faculty of Pharmacy, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. 156 pp.
• Rosselet, J.P. & Reichstein, T., 1953. Die Glykoside von Strophanthus gracilis K. Schum. et Pax. 2. Mitteilung. Odorosid H und Gracilosid. Glykoside und Aglykone. 109. Mitteilung. Helvetica Chimica Acta 36(4): 787–801.
Sources of illustration
• Beentje, H.J., 1982. A monograph on Strophanthus DC. (Apocynaceae). Mededelingen Landbouwhogeschool Wageningen 82–4. Wageningen, Netherlands. 191 pp.
Author(s)
H.J. Beentje
Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, United Kingdom


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:
Beentje, H.J., 2006. Strophanthus preussii Engl. & Pax. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.

















































Distribution Map wild


1, flowering branch; 2, fruit, one follicle removed; 3, seed.
Redrawn and adapted by Iskak Syamsudin



flowering branches


flowering branch


flowering branch


inflorescence


flower