euphorbus — There are many species of plants in the family named for Euphorbus, for instance, the Poinsettia. Many of these species are poisonous, but the poisons of some, for instance the castor bean, are useful in medicine. The “Crown of Thorns” plant Euphorbia Milii is poisonous and daunting in the sharpness of its thorns and the poison oak-like contact dermatitis that it can cause, and legend holds that it is the source of the “crown of thorns” that Christ’s persecutors made him wear in mockery prior to his execution.