Corn Tumours?

I’ve never seen this before. My corn seems to have tumours. Anyone ever experienced this?

UPDATE:

Sean tells me it’s a fungus called black soot, aka corn smut (wikipedia):

Corn smut is a disease of maize caused by the pathogenic plant fungus Ustilago maydis. U. maydis causes smut disease on maize (Zea mays) and teosinte (Euchlena mexicana). Although it can infect any part of the plant it usually enters the ovaries and replaces the normal kernels of the cobs with large distorted tumors analogous to mushrooms. These tumors, or “galls”, are made up of much-enlarged cells of the infected plant, fungal threads, and blue-black spores. The spores give the cob a burned, scorched appearance. In fact, the name Ustilago comes from the Latin word ustilare (to burn).

Considered a pest in most of the United States, smut feeds off the corn plant and decreases the yield. Usually smut-infected crops are destroyed. However, in Mexico corn smut is called huitlacoche (IPA /wi.t͡ɬa.ko.tÍ¡É•e/, sometimes spelled cuitlacoche), an Aztec word reportedly meaning raven’s excrement [1]. It is considered a delicacy, even being preserved and sold for a higher price than corn.

From: Wisegeek.com:

Huitlacoche is the fungal, culinary delicacy Ustilago maydis that grows on ears of corn. Inhabitants of Mexico and indigenous people from the Southwestern United States enjoy this rich, smoky ingredient in foods like tamales, soups, quesadillas, appetizers, and ice cream. While farmers treat huitlacoche as an infectious affliction that ruins corn crops, it has a long history in the cuisine of Aztecs, Hopi, and Zuni.

Henrietta’s Herbal Homepage entry makes me more nervous:

“Its use is attended with shedding of the hair, both of man and beast, and sometimes even of teeth. Mules fed on it lose their hoofs, and fowls lay eggs without any shells” (Rowlin). “It is doubtless by its abortifacient power that it causes the eggs of fowls to be extruded before there has been time for a shell to be formed. By what power does it cause the shedding of the hair of man and brute animals, and the casting off of the hoofs of mules long fed upon it?” (Prof. Tully). “In a cowhouse, where cows were fed on Indian corn infested with this parasite, 11 of their number aborted in 8 days. After their food was changed none of the others aborted” (Annal. Med. Netr. Belge, and Rép. de Ph.). The better to be convinced of the poisonous nature of this fungus, the author, after having dried and pulverized the drug, administered 6 drachms to two bitch dogs with young, which soon caused them to abort” (Dr. H. W. Burt, Amer. Homoeop. Obs., 1868, p. 305).