Thin, membranous, brownish red fronds, to 200 mm long. Frond ± dichotomously divided, becoming irregular in upper parts. Frond often iridescent, with undulate, often proliferous margins, sometimes with flattened hooks or with rhizoidal attachment processes. Very variable in growth form.

A short thallus with a stout midrib arises from a discoid holdfast, widening as it branches into flattened red-brown or red-purple fronds to a height of 20 cm. The fronds are thin and membranous, around 2.5 cm in width and may have a slight blue iridescence under water. Repeated branching gives it a bushy tangled appearance with the branches tapering to rounded tips. Morphology is variable and blades can be either erect or prostrate and broadly-wedged or strap-shaped. Margins may be smooth, undulating, denticulate or hooked. frequently with a blue iridescence underwater.

Link for MarLIN

Loiseaux-de Goër, S. & Noailles, M.-C. (2008). Algues de Roscoff. pp. [1]-215, col. figs. Roscoff: Editions de la Station Biologique de Roscoff.

Maggs, C.A. & Hommersand, M.H. (1993). Seaweeds of the British Isles. Volume 1. Rhodophyta. Part 3A. Ceramiales. pp. xv + 444, 129 figs, map. London: HMSO.

Basionym: Ulva ramosa Hudson

Type locality: Lancaster, England (Silva, Basson & Moe 1996: 900)