Also known as water moulds. Genetically, these are quite unique fungi, generally now classified separately from the Fungi, that are commonly plant pathogenic and lack cross walls.

nonphotosynthetic fungi that resemble algae and that reproduce by forming oospores; sometimes classified as protoctists

A class of aquatic and terrestrial fungi (subdivision Mastigomycotina) that typically produce oogonia and zoosporangia in which form zoospores having one anteriorly-directed tinsel flagellum and one posteriorly-directed whiplash flagellum.