A new genus of the Verrucalvaceae (Oomycetes)

A fungus, isolated from sugar cane in Queensland, Australia and causing the Poor Root Syndrome disease, is described and shown to be related to Verrucalvus and possesses verrucate oogonia containing plerotic oospores; it is placed in the Verrucalvaceae (Sclerosporales). On the basis of morphological and DNA studies the Verrucalvaceae has to be placed in the Saprolegniomycetidae. It follows that the order Sclerosporales (and also the Leptomitales) must be removed from the Peronosporomycetidae and placed in the Saprolegniomycetidae.