Simply put, corn smut. It is a corn disease caused by the fungus Ustilago maydis. It causes the formation of galls, or tumor-like growths on corn kernels. They range is size from 1/2 to 11 inches in diameter, have a black color and release a black inky material when ruptured.
While it may not sound or look pleasant, it is edible and is a delicacy in Mexico and Central America. It has a smoky, earthy flavor and is an excellent source of carbohydrates, protein, fat, vitamins and minerals.
Some chefs are getting creative by using huitlacoche in foods from macaroni and cheese to ice cream!
Intrigued? Learn more at https://hort.extension.wisc.edu/articles/huitlacoche/.