necrotrophic endoparasites of vascular plants and other straminopiles; cause hyptertropy and hyperplasia.

Produce multinucleate, unwalled protoplasts often defined as plasmodia; actually they are plasmodia-like and differ from true plasmodia in that they do no move, can not phagocytize food materials, and are always intracellular.

Primary plasmodium produces thin-walled zoosporangia; zoospores are anteriorly biflagellate with flagella whiplash and of unequal size

Secondary plasmodium produces thick-walled resting spores.

Causative agent of clubroot of cabbage and other brassicaceous crops, powdery scab of potato, crook root of watercress, and rhizomania of sugar beet (pathogen is associated with a virus); also some species serve as vectors for viruses of crops including barley, wheat, potatoes, and water cress.

Cell wall: supposedly chitinous

Zoospores anteriorly uniflagellate, flagellum tinsel.

Zoospores lack a side body complex, microbodies, and lipids but have ribosomes that are aggregated around the nucleus.

Cell wall contains both chitin and cellulose.

Species occur in soil, fresh water, marine habitats, and as hyperparasites on the oospores of Oomycetes and the zygospores of endomycorrhizal fungi.

Presences of an ectoplasmic network of branched, anastomsing, wall-less filaments produced by cells with a specialized cell surface organelle, known as a bothrosome or sagenogen (see Figure 25-2, pg. 746 of your textbook).

Zoospores, when produced, are laterally biflagellate, longer anterior one is tinsel, shorter whiplash is directed posterior.

Found in estuarine and nearshore habitats where they are associated with the leaves of vascular plants, algae, and organic debris

Phylogeny is subject of the PhD thesis of Celest Leander (graduate of HSU; degree in animal physiology but got interested in fungi and is now getting her PhD in mycology under David Porter at the University of Georgia).