Bermuda Smut
Ustilago cynodontis
Photographed in Phoenix, Arizona 7 May 2007. This photo is
hosted at Wikimedia where
there are additional images of
Corn Smut, Ustilago maydis.
Cool, moist weather late in the spring after Bermuda Grass (Cynodon dactylon) has begun flowering seems to lead to seed heads becoming infected with the smut fungus, Ustilago cynodontis. These infected heads are mostly seen in the urban areas of the Sonoran Desert and are readily identfiable by the copious, jet-black, sooty spores.