Pestalotia rhododendri is a plant pathogen infecting azaleas and rhododendrons. Important diseases: Pestalotiopsis tip blight of conifers, Gray leaf spot Pestalotia is primarily a secondary pathogen. It is saprophytic on dead and dying tissues and is weakly parasitic infecting wounds under moist conditions. Dark, disc or cushion-shaped acervuli are formed under the plant epidermis which then splits open revealing the fruiting structures. Conidia are produced on short simple conidiophores within the acervulus.