strophanthus

Strophanthus is a genus of flowering plants in the Apocynaceae family. It is native to tropical Africa and parts of Asia and comprises several dozen species of woody climbers and shrubs. Plants often feature milky sap, opposite leaves, and showy tubular flowers that can be white, pink, or purple. The fruit consists of paired, slender follicles containing numerous seeds with long, silky hairs that aid wind dispersal.

Botanically, Strophanthus species are typically slow-growing vines or shrubs with evergreen foliage. Flowers are arranged in inflorescences and attract various pollinators. The seeds are adapted for wind dispersal due to their hair-like structures, enabling spread across open habitats and forest edges.

Chemistry and medical significance: Many Strophanthus species contain cardiac glycosides. The best known is ouabain, also called strophanthin G, which has been isolated from seeds of Strophanthus gratus and Strophanthus kombé. These compounds have potent effects on heart muscle and have a long history of use in medicine as heart stimulants, as well as in traditional practices. In the 19th and early 20th centuries they were used for heart conditions, but their narrow therapeutic window and toxicity risks limited modern medical use. The plant has also been used historically as a source of arrow poisons by African peoples.

Selected species and notes: Strophanthus gratus and Strophanthus kombé are among the best known for their cardiac glycosides. Some species are cultivated ornamentally in suitable climates, while others are primarily discussed for their ethnobotanical and pharmacological significance.