Ascophyllum noosum is a large, common, brown alga, in the Class Phaeophyceae. It is seaweed of the northern Atlantic Ocean, also known as Norwegian Kelp, Knotted Kelp, knotted wrack or egg wrack. It is common on the north-western coast of Europe (from Svalbard to Portugal) including east Greenland and the north-eastern coast of North America.