Leptosphaerulina

Leptosphaerulina is a genus of fungi in the class Dothideomycetes. The relationship of this taxon to other taxa within the class was unknown in 2007 until it was placed within the Didymellaceae family in the Pleosporales order. The genus was first described by Australian plant pathologist Daniel McAlpine in 1902. Situation: A range of cool season grasses. Turf damage: Uniform yellow or brown lesions may extend down to the leaf sheath. Water-soaked lesions, which quickly fade to a bleached white, may also occur on the leaf blades. Occurrence: Disease outbreaks can occur during warm, humid weather on fescue, ryegrass or bentgrass. Large turf areas become uniformly blighted or appear patchy with individual leaves dying back from the tip.

from Wikipedia