SUMMARYThis account deals with two leafblight fungi occurring on mountain laurel,Kalmia latifoliaL. The diseases caused by both these fungi are quite alike in gross appearance. Ascigerous stages of the pathogens develop on fallen leaves. One causal fungus, aPhysalospora, differs from the five other species known to occur on Ericaceae, and is consequently described asP. kalmiae.The second pathogen has been known only in its conidial state from the District of Columbia. It is believed to be distinct from three other species ofDiaportheinfecting Ericaceous plants, and is described asD. kalmiae.Its conidial stage isPhomopsis kalmiaeEnlows. Material upon which the two taxa were based has been sent to the National Fungus Collection, Washington, D. C.