AKA: Pink Patch
Fungus: Corticium fuciforme 
Symptoms: Coral-pink to red fungus strands may be seen on leaves and leaf sheaths binding leaves together. Affected turf areas are usually more or less circular and vary from 2 to 15 inches in diameter. When dry, the pink strands resemble red threads. The infected leaf first appears water-soaked, but rapidly dies, becoming light tan. Leaves and often the sheaths are killed.
Grasses susceptible: Bentgrass, bluegrass, fescue and ryegrass.
Conditions favoring disease: Red thread is most serious during periods of prolonged cool, wet weather, especially on turf deficient in nitrogen.