Description: Thallus is a cylindrical, yellowish-brown contorted sac that often grows in small clusters. It has an irregular cushion-like base and holdfast. Thallus generally doesn't grow larger than 20 cm (8 in) tall. Habitat: This annual is found in the low intertidal zone growing on rock and prefers semi-protected to semi-exposed habitats. Similar taxa: Coilodesme spp., Colpomenia peregrina, Leathesia marina..