The plants display a light to yellowish-green coloration and have a soft, upright, filamentous structure with irregular branching. They are fragile and contain septate coenocytes. Branching is less frequent in the lower sections of the main stems but becomes more abundant higher up. Initially, the erect stems are flattened and fan-shaped, with branches growing opposite and in a regular pattern. As they develop, the branches become more irregular. These branches are interconnected into a three-dimensional mesh through small specialized cells that can attach one filament to another, either at the tip or along the sides of segments. Over time, anastomoses become more numerous, ultimately forming the mature spongy network.