Albugo bliti, White Rust, is a type of oomycete pathogen of genusAlbugo that affects the tissues of plants. In particular, this white rust is found on Amaranth, beets and lambs quarters. Many discussions of this white rust treat it as a type of fungus.
Keinath, A.P.; Strand, A.E.; Hamilton, R.D. (May 2003). "First Report of White Rust Caused by Albugo bliti on Seabeach Amaranth in the United States". Plant Disease87 (5): 602. doi:10.1094/PDIS.2003.87.5.602B.