Family Description:
Members of this family have bodies that are either tubular and one cell thick or bladelike and two cell layers thick. Most cells contain a single nucleus and a single chloroplast. The chloroplast is flattened to cuplike in shape, and has one to several pyrenoids.
Typically, the alternation of generations shown by members of this family is isomorphic, with sporophytic generations similar to gametophytic generations. When asexual spores are formed, they are motile and bear four flagella. Gametes are biflagellate.

Species description:
Branched String Lettuce differs from the above two species in being richly branched. It can extend to several meters (many feet) in length, and often has abundant short to very long branches (proliferations) along the edges. It grows attached to small rocks or is free-floating on mud in protected habitats.

Source:  North Pacific Seaweeds

Synonyms and Alternate Names:
Enteromorpha prolfera (O.F.Müller) J.Agardh
Enteromorpha prolifera