• Rhodophyta
  • Cyanidium
  • Porphyridiales
  • Compsopogonales
  • Bangiales
  • Florideophyceae

Taxa indicated by '*' are members of the traditional Bangiophyceae/Bangiophycidae that is now considered to be paraphyletic.

Traditionally the red algae were divided into two Classes the Bangiophyceae and Florideophyceae. Alternatively a single Class, the Rhodophyceae and two Subclasses, Bangiophycidae and Florideophycidae are used. Based on ultrastructure and molecular evidence the Bangiophyceae is now accepted as a paraphyletic group, while the Florideophyceae is considered to be monophyletic based on two synapomorphic characters - presence of a filamentous gonimoblast and tetrasporangia (Garbary & Gabrielson 1990 [and references within], Ragan et al. 1994).