Verrucaria rubra, Hildenbrandia prototypus, H. rosea

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: H. occidentalis has regularly zonately divided tetrasporangia; basal crusts of Gloiopeltis and Palmaria.