Strophanthus eminii (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Medicinal

Strophanthus eminii Asch. & Pax

Protologue: Bot. Jahrb. Syst. 15: 366, t. 10, 11 (1892).

Family: Apocynaceae

Vernacular names

• Spider tresses, poison arrow vine (En).
• Msungululu, mtondo (Sw).

Origin and geographic distribution

Strophanthus eminii occurs in south-eastern DR Congo, Tanzania and northern Zambia.

Uses

In DR Congo and Tanzania the roots are used as emetic. The seeds are used in arrow poisons. In Tanzania a root infusion is applied to skin diseases and wounds, and it is taken orally, mostly together with other plants, as emetic and anthelmintic, whereas the vapours are inhaled against fever. Children are bathed in a root decoction to combat fever. Young twigs are chewed against the effects of snakebites. The soft leaves are sometimes used as toilet paper for babies.

Properties

As in many Strophanthus species, a complex mixture of cardiac glycosides (cardenolides) is present in Strophanthus eminii, and the seeds contain the highest concentration. The main glycosides isolated from the seeds are emicymarin and periplocymarin, which have periplogenin as aglycone, cymarin with strophanthidin as aglycone, and cymarol with strophanthidol as aglycone. Ledienoside, with periplogenin as aglycone, has been isolated as a minor compound, and was previously found in Strophanthus ledienii Stein. When used as an arrow poison, these glycosides cause the heart of the prey animal or victim to arrest in systole.

Adulterations and substitutes

If the seeds of Strophanthus eminii are supplied within the fruit, there is no chance of adulteration or substitution, as the fruits are unique within the genus, with the characteristic dense and long fruit wall protuberances. The seed on its own, though, can be confused with many other Strophanthus species.

Description

Shrub or small tree up to 7 m tall or liana up to 10 m long, with clear, white or yellow exudate; stem up to 6 cm in diameter; bark grey or brown; branches sometimes fleshy, sparsely lenticellate, grey or brown. Leaves decussately opposite, simple and entire; stipules absent; petiole 1–10 mm long; blade ovate to elliptical, 6–24 cm × 4–18 cm, base cuneate or rounded, apex acute to acuminate, papery or leathery, densely hairy on both sides. Inflorescence a dichasial cyme, axillary on long or short leafless branches, congested, 1–12-flowered; peduncle 0–4 mm long; bracts ovate to elliptical, 4–15 mm long. Flowers bisexual, regular, 5-merous, fragrant; pedicel 1–8 mm long; sepals free, ovate or narrowly ovate, 11–25 mm long, acute; corolla tube 17–26 mm long, widening between 50–75% of its length into a cup-shaped upper part, pubescent outside, glabrous or short-hairy inside, outside pink with white, turning red, inside white, turning yellow with red spots and streaks, corona lobes subulate, 2.5–6.5 mm long, acute or obtuse, fleshy, papillose, red or purple, corolla lobes ovate, gradually narrowing into a narrow, spreading tail, lobes including the tail 94–180 mm long, hairy outside, glabrous inside, white and turning yellow, the tails orange, turning red; stamens inserted at 9.5–14 mm from the base of the corolla tube, just exserted or just included; ovary half-inferior, 2-celled, style 11–18 mm long, ending in a ring-like pistil head surrounding the minute stigma. Fruit consisting of 2 narrowly ellipsoid follicles 20–38 cm × 1.5–3 cm, tapering into an obtuse apex or knob, 2-valved, divergent at 180°, wall thick, densely set with 4–18 mm long hairy protuberances, many-seeded. Seeds spindle-shaped, 11–24 mm × 2.5–5 mm, densely pubescent, at apex with a long beak up to 11 cm long, glabrous in lower half, upper half with long hairs up to 11 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.

Several Strophanthus species related to Strophanthus eminii have similar uses.

Strophanthus holosericeus

Strophanthus holosericeus K.Schum. & Gilg is a deciduous liana from south-eastern DR Congo and northern Zambia; its seeds are used as arrow poison and ordeal poison.

Strophanthus mirabilis

Strophanthus mirabilis Gilg is a small shrub occurring in Somalia and Kenya; the seeds are used as ordeal poison and the roots are considered edible when cooked.

Strophanthus nicholsonii

Strophanthus nicholsonii Holmes is a shrub occurring in Malawi, Zambia, Zimbabwe and Mozambique; the seeds are used as a hunting poison and ordeal poison.

Growth and development

Strophanthus eminii flowers at the end of the dry season and the beginning of the rainy season, with the flowers appearing before or together with the leaves. Mature fruits are found in the dry season.

Ecology

Strophanthus eminii occurs in deciduous woodland or Acacia- Commiphora bushland, especially in rocky localities, at 600–1650 m altitude.

Genetic resources

As Strophanthus eminii is distributed over a fairly large area in common habitats, it is not threatened by genetic erosion.

Prospects

If pharmacological interest in Strophanthus is revived, it might be worth investigating the pharmacological potential of Strophanthus eminii, as it is chemically similar to better-known species, e.g. Strophanthus hispidus DC. and Strophanthus kombe Oliv. Because of its beautiful flowers, Strophanthus eminii would make an interesting ornamental.

Major references

• Beentje, H.J., 1982. A monograph on Strophanthus DC. (Apocynaceae). Mededelingen Landbouwhogeschool Wageningen 82–4. Wageningen, Netherlands. 191 pp.

• Neuwinger, H.D., 1996. African ethnobotany: poisons and drugs. Chapman & Hall, London, United Kingdom. 941 pp.

• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.

Other references

• Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.

• Githens, T.S., 1948. Drug plants of Africa. African Handbooks: 8. University of Pennsylvania Press, Lancaster Press, Lancaster, United States. 125 pp.

• Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp.

• Lardon, A., 1950. Die Glycoside der Samen von Strophanthus eminii Asch. & Pax. Glykoside und Aglykone, 56. Mitteilung. Helvetica Chimica Acta 33(3): 639–650.

• Von Euw, J. & Reichstein, T., 1948. Die Glykoside der Samen von Strophanthus nicholsonii Holm. Glykoside und Aglykone. 34. Mitteilung. Helvetica Chimica Acta 31(3): 883–892.

• 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.

• Zelnik, R. & Reichstein, T., 1957. Die Glykoside der Samen von Strophanthus eminii Asch. & Pax, 3. Mitteilung. Glykoside und Aglykone, 184. Mitteilung. Helvetica Chimica Acta 40(7): 2110–2129.

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

Correct citation of this article

Beentje, H.J., 2006. Strophanthus eminii Asch. & Pax. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 17 September 2026.

• See the Prota4U database.