Acokanthera

About

Acokanthera is a genus of flowering plants in the family Apocynaceae. It comprises 5 species and is generally restricted to Africa, although A. schimperi also occurs in Yemen. Its sap contains the deadly toxin ouabain, a glycoside that causes heart failure. The sap is among the most commonly used in arrow poisons, including those used for poaching elephants.

Summary from Wikipedia