• Kelp, Diatoms, and Allies (Kingdom Chromista)

• Phylum Ochrophyta

• Brown Algae (Class Phaeophyceae)

• Subclass Fucophycidae

• Order Ralfsiales

• Family Ralfsiaceae

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​Family Ralfsiaceae is a family of brown algae belonging to the order Ralfsiales and class Phaeophyceae. Members of this family are predominantly marine and are characterized by their crustose thalli, which form thin, firmly attached brown crusts on rocks, shells, and other hard substrates in intertidal and shallow subtidal zones. The thallus is composed of closely packed filaments that create a compact structure capable of withstanding wave action, desiccation, and other environmental stresses.