Viridiplantae Cavalier-Smith, 1981 - green plants see Subkingdom Viridiplantae Caval.-Sm. (1981) Chlorophyta Pascher (1914) - green algae core chlorophytes Class Ulvophyceae K.R. Mattox & K.D. Stewart (1984) - ulvophytes Ulvales-Ulotrichales Genus Halochlorococcum P.A. Dangeard (1965)