Egregia menziesii is a species of kelp known commonly as feather boa kelp. It is native to the coastline of western North America from Alaska to Baja California, where it is a common kelp of the intertidal zone. It is dark brown in color, shiny and bumpy in texture, and may reach over five meters long. It grows a branching stipe from a thick holdfast. It bears long, flat, straplike fronds lined with small blades each a few centimeters long. There are pneumatocysts at intervals along the fronds which provide buoyancy. The alga varies in morphology; the rachis, or central strip, of the frond may be smooth or corrugated, and the blades along the edge of the rachis may be a variety of shapes.