Sea lettuce

Sea lettuce

┬ęDorset Wildlife Trust

Sea lettuce

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Scientific name: Ulva lactuca
Sea lettuce is unmistakeable - most often a bright green and always translucent, it is found on all UK coasts.

Top facts


Length: up to 20cm Frond width: up to 30cm

Conservation status


When to see

January to December


Sea lettuce is a common seaweed, found attached to rocks and other surfaces using a small holdfast or living in rockpools if it has become detatched. The detatched fronds continue to grow and can create large floating colonies. The ruffled fronds are unique - bright green and translucent, being only 2 cells thick. It is this ruffling that gives it the name sea lettuce - as it looks a bit like a lettuce leaf! (The word lactuca in its scientific name means lettuce).

What to look for

Sea lettuce lives up to its name: it looks like green, floppy lettuce leaves which are often tatty in appearance but are quite tough.

Where to find

Found on all UK coasts.

Did you know?

Sea lettuce is sometimes eaten as 'Green laver' but 'Purple laver' (Porphyra umbilicalis) is much preferred. Both are used to make laver bread - a Welsh speciality - and are also used to complement rice in Japanese and Korean cooking.