Drupes are fruits that are fleshy on the outside, but contain a shell with a seed on the inside. Cashew plants belong to a group of plants known as anacardiaceae, which includes mango, sumac and ...

The trees are a member of the same family as poison ivy, and like poison ivy, cashew plants contain a toxin called urushiol. It's found in the plant itself and the brown oil inside a nut's shell.