Large-leaved seaweed: Wrinkled and curled, dark brown, sometimes covered with a white bloom, 30-60 cm long. The main stem is cylindrical with conical protrusions. Main branches grow from both sides of the main stem, while lateral branches grow from the leaf axils of main branches, with short, spiny protrusions. Primary leaves are lanceolate or obovate, 5-7 cm long and about 1 cm wide, entire or coarsely serrated; secondary leaves are linear or lanceolate, with small branchlets bearing linear leaves in the leaf axils. Air sacs are dark brown, spherical or ovoid, some with stalks, with a blunt, rounded apex, some with a short, fine point. Brittle, soft when moist; swells, fleshy, and slimy after soaking in water. Has a fishy odor and a slightly salty taste.
Small-leaved seaweed: Smaller, 15-40 cm long. Branches are alternate, without spiny protrusions. Leaves are linear or slenderly spatulate, slightly swollen at the apex, hollow. Air sacs are axillary, fusiform or spherical, with relatively long stalks. Relatively hard.
