Strophanthins are cardiac glycosides in plants of the genus "Strophanthus". British troops were the target of arrows poisoned with the extracts of various "Strophanthus" species. The larva feeds on "Strophanthus" "dichotomus". Galenical preparations of strophanthus came to be commonly prescribed for cardiac patients. On this expedition he studied the distribution, prevalence and behavior of "Strophanthus" plants. These glycosides are found in the plant genera "Digitalis", "Scilla", and "Strophanthus". Several African tribes used "Strophanthus" as the principal ingredient in arrow poison. Baldwin discovered that "Strophanthus sarmentosus" was a natural source of the steroid hormone cortisone. "Strophanthus kombe" is found growing naturally in the tropical regions of southeast Africa. Dr. Feilchenfeld of Berlin administered strophanthus as premedicant before anesthesia. "Strophanthus kombe" is known for its historical use as a source of arrow poison. "Strophanthus sarmentosus" is native from west and central tropical Africa to Uganda and Angola. Albert Fraenkel, pharmacologist in Heidelberg, saw strophanthus as therapeutical in cardiac failure (emergency cases initially).