Description: Thallus is a rose-to brownish-red, uncalcified crust that adheres tightly to rock. It is very thin (0.3 mm or 0.01 in thick), can appear partly transparent, and grows very slowly. Tetrasporangia, which are irregularly divided and occur in conceptacles, are the only known form of reproduction. Habitat: This crustose species is found throughout the year on emergent rock and in tidepools from the high intertidal to shallow subtidal of protected to exposed habitats. Similar taxa: Hildenbrandia occidentalis has regularly zonately divided tetrasporangia; also similar to basal crusts of Gloiopeltis and Palmaria.