Scientific examination was brought to bear, and the cause was found to be a parasitic nematode which attacked the roots of the plant.
"The Khedive's Country"
George Manville Fenn
This cannot be taken as meaning that any poison protects against any parasite, however, for Euphorbia is itself subject to attacks of Uredineae, and Pangium edule, which contains prussic acid and is extremely poisonous to most animals, is eaten with avidity by several insects, while nematode worms can live in its tissues.
"Disease in Plants"
H. Marshall Ward