Forkweed

Appearance

Thalli erect, light to dark brown, attached to the substrate by a small discoid holdfast. Branching regularly dichotomous, forming angles of 15° to 35°. Branches strap-shaped, 3 to 6 mm wide, broadest below each fork. Apices of terminal segments emarginate. Blade margin entire with occasional short stubby spines. Cross-section of a branch shows 3 layers of cells, consisting of a middle layer of large, rectangular cells, and bounded on the upper and lower surfaces by a layer of small, cuboidal and pigmented cortical cells. Thalli up to 14 cm in height.

Naming

Also called Forked Ribbons.

Distribution

Widespread. Throughout the British Isles from the Shetlands to the Channel Islands, though less common on the eastern shores of England. Europe: Mediterranean, Azores, Portugal, Atlantic coasts of Spain and France, Baltic Sea and Norway. Atlantic coast of North America: Virginia. Further afield: Jamaica, Salvage Islands, Canary Islands, Mauritania to South Africa, Mauritius, Australia and Tasmania, Japan and Phillipine Islands.

Status

Not Evaluated.

Habitat

Grows abundantly in shallow waters throughout the year; also found on rocks below the low tide mark at calm open coasts and sheltered coasts though some have been reported from a depth of 55 m

Uses

A good source of alginate, an emulsifying, stabilizing and gelling agent in several food products such as frozen food, pastries, jellies, salad dressings, ice cream, meat and flavor sauces, beer, fruit juices, and milk shakes.