Cystophora retroflexa is a brown alga species in the genus Cystophora. It found is found off the coasts of New Zealand and Australia. It is the type species of the genus. Prefers more sheltered environments compared to other Cystophora species, often found in sheltered reefs from 0 to 12 m in depth.
It is a large, open species with floats longer (4âÂÂ10 mm) than broad (3âÂÂ6 mm). The final branches are long (20âÂÂ60 mm) and thin (1âÂÂ2 mm). The side branches have smaller branches arising at irregular intervals from all sides, rather than the seaweed having branches in the one plane.
This species contains phlorotannins of the classes of phlorethols and fucophlorethols (phloroglucinol, difucol, , , , , , , , , , , , , , diphlorethol, , , , , , , , , , , , , and ). There are also halogenated phlorethols and fucophlorethols (chlorinated, brominated and iodinated derivatives).