Recent investigations into the toxicity of known and unknown poisonous plants in the Union of South Africa. XI

Abstract

The toxicity of sixteen plants was investigated. According to the available literature the following three plants were proved for the first time to be toxic: Senecio pterophorus DC; Kalanchoe paniculata Harv., Kalanchoe thyrsiflorae Harv. The results obtained in the experiments with Crotalaria rhodesiae Baker f. and Pseudogaltonia clavata (Baker) Phillips are not considered sufficiently conclusive to prove these two plants to be poisonous. The latex of Arauya serisifera Brot. was proved to possess irritant properties when applied to the skin. The Senecio alkaloids, isatidine and retrorsine, administered per os to horses induced symptoms, post-mortem appearances, and histological lesions typical of those of "dunsiekte" in horses, and these alkaloids are undoubtedly the active principles of the species of Senecio from which they were isolated.