Phyllactinia poinsettiae sp. nov.: a new species of powdery mildew on poinsettia from Indonesia.

Poinsettia (Euphorbia pulcherrima, Euphorbiaceae) is a flowering plant indigenous to Mexico and Central America. The poinsettia is largely known for its red bracts and green foliage, and is widely used in winter festivities around temperate regions such as Christmas floral displays. A powdery mildew was found on this plant species in Java and Bali Islands of Indonesia in 2013. Morphological and molecular analyses revealed that this species is new to science. It is an asexual morph belonging to the genus Phyllactinia (syn. Ovulariopsis). The new species is described and illustrated as Phyllactinia poinsettiae sp. nov.