Pachymeniopsis lanceolata is a red alga, formerly placed in the genus Grateloupia. It has wide leaf-like or strap-like blades, 300–500 mm long, and and 70–70 mm wide. Pachymeniopsis lanceolata ranges from brown to red. This seaweed is native to the northwest Pacific including China, Japan, and Korea. It was first collected in 2003 in California on Santa Catalina Island, and in 2008 at Moss Landing. Subsequently, it was found in Los Angeles Harbor, and San Francisco Bay. It occurs on rocks, docks, pontoons, seawater pipes, and mooring lines.