Species:

Note: The species is perennial and common in the intertidal zone. The thallus is flat and often channelled and twisted, with repeatedly dichotomous branching. Several erect fronds normally grow from the attachment disk. Two main types of life cycles are known for the species; 1) a diplohaplontic life cycle where the erect fronds represent the gametangial phase and the tetrasporophytic phase grows as thick crusts on the substratum (known as the ‘Petrocelis’ phase), and 2) an apomictic life cycle where spores from the erect thallus grow to new erect thalli.