A group of protists that live endoparasitically in plant cells. They there form multinucleate cells, plasmodia. The ultimately divide into spores that are liberated when the plant cell disintegrates. Spores can be in the form of resting spores or motile zoospores, that bear two smooth flagellae of unequal length. In the past they were considered to belong to the myxomycetes, slime molds. They also are addressed as Plasmodiophorida.
Neuhauser, Huber & Kirchmair (2009a), Neuhauser, Kirchmair & Gleason (2011a), Tree of Life (2016).