Thicketweed is a delicate-looking seaweed, just like its family member hen pen. However, the fronds look more like tufts than feathers. It consists of a single cell with many cell nuclei, without partitions. In the Netherlands, thicketweed is only found in the delta region, particularly in the Grevelingen, and in brackish water canals. It grows well near freshwater nutrient-rich inlets.