This form of brown algae is commonly known as a Sea Palm due to its obvious similarity in shape to a palm tree. It is more correctly known as Postelsia. It can be identifed by a single thick stem topped by flowing blades. At the bottom of the stem is a hold-fast which anchors the plant to the substrate and allows it to survive even where the surf is rough. The Sea Palm is unique in that it’s one of the few forms of algae which can survive for long periods of time when exposed to air. In fact, the Sea Palm may spend of the majority of its life in the open area.
Like many forms of algae, the Sea Palm reproduces by shedding spores into the open water which will lodge in the crevaces in rocky surfaces. Often the plant will grown in thick clusters which may represent several generations.
Sea Palm can be found all along the west coast of North America from British Columbia to central California. In Oregon, it can be easily found in rocky tidal areas, usually where there is constant wave action and access to sunlight in order to stimulate photosynthesis.
Photo credit: NOAA.