Strophanthus

Strophanthus
File:Strophanthus preussi0.jpg
Strophanthus preussii
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Gentianales
Family:	Apocynaceae
Genus:	Strophanthus DC., 1802
Species
See text.

Strophanthus is a genus of 35-40 species of flowering plants in the family Apocynaceae, native mainly to tropical Africa, extending to South Africa, with a few species in Asia, from southern India to the Philippines and southern China. The name (strophos anthos, "twisted cord flower") derives from the long twisted threadlike segments of the corolla, which in one species (S. preussii) attain a length of 30–35 cm.

The genus includes vines, shrubs and small trees. The leaves are opposite or whorled, simple broad lanceolate, 2–20 cm long, with an entire margin.

Several of the African tribes used Strophanthus as the principal ingredient in arrow poison.

Species

• Strophanthus aambe
• Strophanthus alterniflorus
• Strophanthus amboensis
• Strophanthus annamensis
• Strophanthus arboreus
• Strophanthus arnoldianus
• Strophanthus aurantiacus
• Strophanthus barteri
• Strophanthus bequaertii
• Strophanthus boivinni
• Strophanthus brevicaudatus
• Strophanthus bullenianus
• Strophanthus capensis
• Strophanthus caudatus (tropical Asia)
• Strophanthus chinensis (southern China, Vietnam)
• Strophanthus congoensis
• Strophanthus courmontii
• Strophanthus cumingii
• Strophanthus dichotomus
• Strophanthus divaricatus (southern China; { Vietnam)
• Strophanthus eminii (east Africa; poison: e-strophanthin)
• Strophanthus glabra
• Strophanthus gratus (tropical west Africa; poison: ouabain, g-strophanthin)
• Strophanthus hispidus (Togo, Cameroon)
• Strophanthus laurifolinus
• Strophanthus kombe (east Africa; poison: k-strophanthin)
• Strophanthus nicholsoni
• Strophanthus petersianus (tropical Africa)
• Strophanthus preussii (tropical west Africa)
• Strophanthus sarmentosus (tropical Africa)
• Strophanthus scandens (Mallacca)
• Strophanthus speciosus (South Africa)
• Strophanthus thallone
• Strophanthus vanderijstii
• Strophanthus welwitschii

Pharmacology

Plants from this genus produce toxic alkaloids and cardiac glycosides g-strophanthin (syn. ouabain), k-strophanthin and e-strophanthin. As ordinarily administered, the drug acts on the heart before influencing any other organ or tissue. Often indeed no other action can be observed. It is used to produce the drug Ouabain which was taken as a cardiac stimulant to treat heart failure, and is similar to the drug Digoxin produced from Digitalis purpurea.

Notes and references

•  This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press. 

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