Sea Lettuces and Allies

Ulvales is an order of green algae in the class Ulvophyceae. Algae of this order are most commonly found in aquatic habitats (mainly marine or brackish waters); some are found in fresh water or are terrestrial. They are found free-floating, attached to a substrate, or endophytic. Well-known examples include Ulva (including Enteromorpha), which is commonly known as sea lettuce and is a ubiquitous seaweed.

The Ulvales consist of macroscopic or microscopic algae with diverse morphologies (filamentous, pseudoparenchymatous, tubular or blade-like). Cells generally contain a single parietally placed chloroplast with one or multiple pyrenoids, and one or multiple nuclei.