Description: Thallus is a monostromatic blade that can vary in color from pale pink to grayish-purple and in shape from circular to elongate, reaching 30 cm (12 in) in diameter. When reproductive, male and female cells are segregated on different halves of the thallus. Habitat: This ephemeral occurs on rock in summer in the mid to low intertidal of semi-protected to semi-exposed habitats. Similar taxa: Pyropia kurogii, a spring species, is usually smaller, more ovate, and a paler color. Boreophyllum spp.