See text Rozella is a fungal genus of obligate endoparasites of a variety of hosts, including Oomycota, Chytridiomycota, and Blastocladiomycota.

[5] Considered one of the earliest diverging lineages of fungi, the widespread genus contains 27 species, with the most well studied being Rozella allomycis.

As growth continues, the thallus will either form a zoosporangium using the wall of the host or a thick-walled resting spore that can be smooth or spiny.

[7] The genus name of Rozella is in honour of Ernest Roze [ro] (1833–1900), who was a French Administrator and high official in the Ministry of Finance of France, botanist (Bryology, Mycology and Algology).

[10] French mycologist Marie Maxime Cornu in 1872 circumscribed the genus to accommodate four species: R. septigena, R. monoblepharidis-polymorphae, R. rhipidii-spinosi, and R. apodyae-brachynematis.

Additionally, molecular phylogenies consistently group monosporangiate and polysporangiate species together, thus validating the monophyly of the genus.

[7] Rozella allomycis can parasitize multiple Allomyces species, including A. macrogynus and A. arbuscula.

[4] The infection tube causes an invagination of the host cell membrane, which then envelopes the R. allomycis protoplast.

As the infection progresses, R. allomycis protoplasts will instead form resting spores with thick, spiny walls.