| Name | Notes |
|---|---|
| veined tongue weed | Apoglossum ruscifolium (delesseriaceae) |
| Key criteria: | Fairly large (to 10 cm) compound-bladed species growing both intertidally and subtidally on sheltered to strongly wave- exposed shores in a wide range of habitats including rock pools. This species is difficult to confuse with algae other than Hypoglossum hypoglossoides and is common in the subtidal. The lack of records from eastern coasts presumably reflects the lack of hard substrata as well as limited subtidal surveying. intertidal subtidal rock sheltered exposed pool |
| sea beech | Delesseria sanguinea (delesseriaceae) |
| Key criteria: | Large (to 30 cm) blade-like species growing both intertidally and subtidally on wave-exposed shores in a wide range of habitats including deep lower-shore rock pools but mostly subtidally where it is very abundant. Its ease of identification and abundance are indicated by the large number of records. intertidal subtidal rock exposed pool |
| red flags | Dilsea carnosa (dumontiaceae) |
| Key criteria: | Medium to large fleshy spoon-shaped blades. Epilithic in lower shore pools and rocks to at least 35 m. Common and widespread. Large numbers of records partly reflect ease of recognition. epilithic rock pool |
| under tongue weed | Hypoglossum hypoglossoides (delesseriaceae) |
| Key criteria: | Large (to 30 cm) species with narrow much-branched blades growing both intertidally and subtidally in a wide range of habitats on very sheltered to extremely exposed coasts. It grows epiphytically on many larger algae as well as on bedrock and pebbles. Its ease of identification broad range of habitats and abundance are reflected in the large number of records. epiphyte intertidal subtidal rock sheltered exposed |
| winged weed | Membranoptera alata (delesseriaceae) |
| Key criteria: | Large(to 20 cm) species with narrow much-branched blades growing both intertidally and subtidally in a wide range of habitats with hard substratum most abundant subtidally on kelp stipes. Its ease of identification broad range of habitats and abundance are reflected in the large number of records. intertidal subtidal |
| sea oak | Phycodrys rubens (delesseriaceae) |
| Key criteria: | Large (to 30 cm) blade-like species with undulate margins giving the appearance of an oak leaf growing both intertidally and subtidally in wave-exposed shores in a wide range of habitats including deep lower- shore rock pools but mostly subtidally where it may be very abundant. Its ease of identification and abundance are indicated by the large number of records. Virtually absent from south-eastern England. intertidal subtidal rock exposed pool |
A Check-list and Atlas of the Seaweeds of Britain and Ireland. F. G. Hardy and M. D. Guiry. The British Phycological Society, 2003. ISBN 0 9527115 16 Seaweeds of Britain and Ireland. Bunker, Brodie, Maggs and Bunker. Seasearch 2012.