Oldest multi-plant arrow poison

A 7,000-year-old arrow poison found in a bovid bone collected in the 1980s from the Kruger Cave, a Later Stone Age site in the Magaliesberg mountains west of Pretoria in South Africa, is proposed to be the oldest multi-plant component arrow poison based on chemical analysis. While older arrow poisons are known to have been used as hunting weapons, analysis of the Kruger Cave arrow poison detected two potent plant toxins, digitoxin and strophanthidin, indicating it comprised a mixture of poisonous plants. The chemical ricinoleic acid was also present, suggesting it may have contained a third plant, castor beans (Ricinus communis) and therefore potentially another plant poison (i.e., ricin). The findings were published in the journal iScience on 20 December 2024.

Strophanthus species have been used historically in arrow poisons and are a plant source of strophanthidin, a cardenolide-type chemical. Digitoxin occurs in poisonous Digitalis species (commonly known as foxgloves) and is a type of cardiac glycoside chemical. Both digitoxin and strophanthidin can have toxic effects such as altering heart and nerve function.