Description: Thallus is a dark brown blade, two cell layers thick, nearly circular to irregular in outline, reaching 60 cm (27 in) in diameter. Male and female reproductive cells are on separate thalli or on different lobes of the same thallus. Habitat: These two species are annuals; they occur in the mid intertidal of semi-protected to exposed habitats. Similar taxa: Porphyra norrisii^, P. schizophylla