This is very common in all varieties of pines. To improve marketability and provide the Christmas green color that people desire, growers will often spray the trees with an FDA-approved liquid acrylic colorant. "Colorants are very safe, they're non-toxic to anybody who were to put it in their mouth," says Nilssen.

Gunpowder tree or charcoal tree, which was used for making charcoal for gunpowder, is native throughout the old world tropics and weedy on most major Hawaiian Islands.