Numerous plant species harbor toxic compounds, which may be lethal even in small concentrations, and are thus defined as poisonous.
These substances can be present in greater quantities in the flowers, fruits, seeds, leaves, or can be uniformly distributed throughout the plant; the effects caused by such active ingredients can range from simple stomachaches to convulsions, coma, and cardiac arrest. Some poisonous species, such as Atropa belladonna (deadly nightshade), Taxus baccata (yew), and Digitalis purpurea (foxglove), have medicinal properties; other species are common in gardens as ornamental plants such as Ricinus communis (castor bean), Nerium oleander (oleander), Datura arborea (thorn apple), and Prunus laurocerasus (cherry laurel).
Sistema Museale di Ateneo