Littlers' major functional forms and invasive macroalgae.
| Division | Sheets or Thin Blades | Filaments or Cylinders | Coarsely Branched | Thick or Leathery |
| Chlorophyta | Ulva spp image |
Cladophora sericea image |
Caulerpa
taxifolia
image |
Avrainvillea
amadelpha image |
| Dictyosphaeria cavernosa image |
Codium fragile | |||
| Phaeophtya | Colpomenia
peregrina image |
Pilayella spp image |
Sargassum muticum | Undaria pinnatifolia |
| Dictyota spp image |
||||
| Rhodophyta | Grateloupia
doryophora image |
Hypnea musciformis image |
Gracilaria salicornia image |
Kappaphycus
striatum image |
| Asparagopsis
armata image |
||||
| Antithamnionella
spirographidis image |
||||
| Polysiphonia
harveyi
image |
British site - Joint Nature Conservation Commission list of non-native marine species
