| Name | Notes |
|---|---|
| green tarantula weed | Acrosiphonia arcta (acrosiphoniaceae) |
| Key criteria: | This species is commonly encountered on a wide range of shores both as a mid-intertidal large filamentous plant and an upper intertidal turf-forming plant. Although widespread it is probably overshadowed by more abundant Cladophora species resulting in a little under-recording. It is likely that it occurs around most of Britain. upper intertidal intertidal |
| silky thread weed | Derbesia marina (derbesiaceae) |
| Key criteria: | This plant occurs subtidally with two generations in the life-history: a coenocytic (non-cellular) filamentous phase and a vesicular sexual phase. It is likely to occur on all coasts in the area although not commonly. subtidal |
| spongy weed | Spongomorpha aeruginosa (acrosiphoniaceae) |
| Key criteria: | This species occurs mainly as an epiphyte on larger algae in the lower intertidal and subtidal. It is very similar to Acrosiphonia arcta with which it might be confused. While not quite as common as A. arcta it is likely that it occurs on all coasts in the area and is probably present in the large tracts of coastline from which it appears absent from the records. epiphyte lower intertidal intertidal subtidal |
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.