Iris Leaf Spot on Bearded Iris Leaf spot or blotch is one of the common and widespread diseases affecting Iris varieties and daylilies. Both bulbous and rhizome type Irises get affected by this fungal disease. Bearded Irises are often at great risk of the fungal infection. This disease is caused by the fungus Mycosphaerella Macrospora, earlier known as Didymellina Macrospora. …