The Aztec named this dark growth found on corn huitlacoche which translates (rather bluntly and literally) to "ravens excrement". Although the name provided is not overly appetizing the Aztec's fashioned the fungus into dishes of crepes, soups, and tamales.
American farmers call it "smut" and "devil's corn" and consider it a disease to be irradiated. The peoples of Mexico as well as the American Hopi Indians consider the fungus a delightful delicacy.
According to Betty Fussell in her book The Story of Corn, the Hopi call the corn fungus nanha and collect when it is young and tender, par boil it for 10 minutes then sautéd in butter until crisp.
The Zuni Indians call the corn fungus corn-soot and say it symbolizes the "generation of life".
The French call it goitre du mais. It is unclear if it is eaten in France.
Today in Mexico the product is actually cultivated each season providing an ample supply to be eaten fresh, then frozen and canned. While the product is not easy to find in the U.S. most typically huitlacoche can be purchased canned.
Another interesting story told by Ms. Fussell is that of a dinner presented by the James Beard House in New York City in 1989. The purpose was to give Americans a tasting of the corn smut but with a new name "Mexican Truffle". The menu was created by Josefina Howard of Rosa Mexicano restaurant and included huitlacoche appetizers, soup, crepes, tortilla torte, and even an huitlacoche ice cream.
If you live in an area with a large corn crop, or if you have a garden you may find fresh huitlacoche. Here are some preparation instructions.
Carefully pull the husks away from the ear of corn and remove them. Pull away the corn silks and discard. Use a sharp knife and cut the corn kernels from the cob slicking close to the cob as possible keeping your knife parallel to the cob. Remove any additional corn silks that still adhere to the huitlacoche. Roughly chop the huitlacoche (there will be bits of corn adhered to the product).
The huitlacoche can be prepared (cooked) with garlic and chiles and used in crepes, quesadillas, or tacos. Or the product can be used "fresh" in soups or stews.