Brown patch in turf.

Tannish lesions on leaf blades are a symptom of brown patch.

Mycelium growing between leaves of grass. All photos were found at: http://www.cals.ncsu.edu/plantpath/extension/fact_sheets/Turfgrass_-_Managing_Brown_Patch_in_Tall_Fescue_Landscapes.htm as part of a fact sheet on brown patch in tall fescue.