head smut

American  

noun

Plant Pathology.

1. a disease of cereals and other grasses, characterized by a dark-brown, powdery mass of spores replacing the affected seed heads, caused by any of several smut fungi of the genera Sorosporium, Sphacelotheca, and Ustilago.

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Example Sentences

It looks normal, but the plant’s flowers contain spores of head smut instead of its own seeds.

From New York Times

Another fungus, called head smut, had effectively castrated the plant.

From New York Times