Seaweed
"Seaweed" is a colloquial term and lacks a formal definition. A seaweed may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae. As these three groups do not have a common multicellular ancestor, the seaweed are in a polyphyletic group. In addition, some tuft-forming bluegreen algae (Cyanobacteria) are sometimes considered to be seaweed.
Pylaiella
Pylaiella (mung) is a genus of seaweed (brown algae) that can be a nuisance due to its ability to coat people, ropes, animals, and more when it blooms close to the shore under particular conditions.