Description: The light brown thallus is anchored by a sturdy discoidal holdfast and the stiff stipe branches radially to give rise to several main branches, long secondary branches, and finally short terminal branchlets. The terminal branchlets carry small oval, air-filled bladders (pneumatocysts) that can be single, paired, or in short chains terminating in a small pointed projection. The entire thallus can reach up to 5 m (16 ft) tall and form a canopy. Habitat: This perennial is found on rock in the low intertidal and subtidal zones of semi-exposed habitats. Similar taxa: Sargassum muticum.