A common green alga near the top of the shore, on rocks or other algae, on open coasts or in estuaries and harbours, where it may grow mixed with U. intestinalis or other species of the genus. It is better known as Enteromorpha prolifera, but Enteromorpha is now considered to be part of the genus Ulva (Maggs et al., in Brodie et al, 2007).

The fronds are tubular, though often more or less flattened, little to much-branched. The arrangement of the cells, in longitudinal and transverse rows in the central part of the frond, is characteristic of this species, as are the cylindrical chloroplasts seeming to fill the cell and the usually single, central pyrenoids. Critical identification details are provided by Burrows (1991) (as Enteromorpha prolifera) and updated and clarified by Maggs et al., in Brodie et al (2007).

Brodie, J., Maggs, C.A. & John, D.M. (2007). Green seaweeds of Britain and Ireland. pp. [i-v], vi-xii, 1-242, 101 figs. London: British Phycological Society.

Dawes, C.J. & Mathieson, A.C. (2008). The seaweeds of Florida. pp. [i]- viii, [1]-591, [592], pls I-LI. Gainesville, Florida: University Press of Florida.

Hayden, H.S. & Waaland, J.R. (2004). A molecular systematic study of Ulva (Ulvaceae, Ulvales) from the northeast Pacific. Phycologia 43: 364-382.

Leliaert F., Zhang X., Ye N., Malta E.J., Engelen A.E., Mineur F., Verbruggen H. & De Clerck O. (2009). Identity of the Qingdao algal bloom. Phycological Research 57: 147-151.

Lindeberg, M.R. & Lindstrom, S.C. (2010). Field guide to the seaweeds of Alaska. pp. [i-]iii-iv, 1-188, numerous col. photographs. Fairbanks: Alaska Sea Grant College Program.

Pedroche, F.F., Silva, P.C., Aguilar-Rosas, L.E., Dreckmann, K.M. & Aguilar-Rosas, R. (2005). Catálogo de las algas marinas bentónicas del Pacífico de México. I. Chlorophycota. pp. i-viii, 17-146. Ensenada, México: Universidad Autónoma de Baja California.

Sfriso, A. (2011). Chlorophyta multicellulari e fanerogame acquatiche. Ambiente di transizione italiani e litorali adiacenti. pp. [1]-318, pls 1-94. Bologna: Arpa Emilia-Romagna.