Common marine algae that are "feathery red"

NameNotes
siphoned feather weed Heterosiphonia plumosa (dasyaceae)
Key criteria: Large (to 30 cm) robust polysiphonous 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 readily identifiable and very abundant in the subtidal. The infrequency of records from eastern coasts presumably reflects the lack of hard substrata as well as limited subtidal surveying. intertidal subtidal rock sheltered exposed pool
soft feather weed Plumaria plumosa (ceramiaceae)
Key criteria: Robust and conspicuous filamentous species found intertidally on almost every shore particularly abundant on damp vertical surfaces. Difficult to confuse except for some robust specimens that resemble Ptilota gunneri. The absence of records from the area around the Wash is presumably due to a lack of suitable substrata. intertidal
feathered wing weed Ptilota gunneri (ceramiaceae)
Key criteria: Robust large filamentous species very abundant on Laminaria hyperborea stipes throughout Ireland in northern Britain southwards to North Wales. Within these areas its distribution mirrors that of L. hyperborea. epiphyte

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.