An educational resource dedicated mainly to the photography
and diversity of marine life that can be found in coastal waters
and intertidal areas of Great Britain and Ireland by David Fenwick.

Green seaweed / algae images (Chlorophyta)
Chlorodendrophyceae (Class) > Chlorodendrales (Order) > Chlorodendraceae (Family)

Tetraselmis convolutae (Parke & Manton) R.E.Norris, Hori & Chihara, 1980 - A green alga
Tetraselmis marina (Cienkowski) R.E.Norris, Hori & Chihara, 1980 syn. Prasinocladus marinus - A green alga

Chlorophyceae (Class) > Chlamydomonadales (Order) > Chlorochytriaceae (Family)

Chlorochytrium cohnii E.P.Wright, 1877 - An endophytic
single celled green alga in tubes of the colonial diatom
Berkeleya rutilans

Chlorophyceae (Class) > Chlorocystidales (Order) > Chlorocystidaceae (Family)

Halochlorococcum moorei (N.L.Gardner) Kornmann & Sahling, 1983 - Parasitic green alga on Blidingia minima

Chlorophyceae (Class) > Sphaeropleales (Order) > Microsporaceae (Family)

Microspora ficulinae P.J.L.Dangeard, 1932
- Parasitic green algae of sponge Halichondria

Microspora ficulinae P.J.L.Dangeard, 1932
- Parasitic green algae of sponge Suberites

Microspora ficulinae P.J.L.Dangeard, 1932
- Parasitic green algae of sponge Hymeniacidon

Trebouxiophyceae (Class) > Prasiolales (Order) > Prasiolaceae (Family)

Prasiola calophylla (Carmichael ex Greville) Kützing, 1845
- A terrestrial algae that is often found in maritime areas

Prasiola stipitata Suhr ex Jessen, 1848
- A Green Guano Weed

Ulvophyceae (Class) > Bryopsidales (Order) > Bryopsidaceae (Family)

Bryopsis hypnoides J.V.Lamouroux, 1809
- Variously Branched Mossy Feather Weed

Bryopsis plumosa (Hudson) C.Agardh, 1823
- Evenly Branched Mossy Feather Weed

Caulerpa taxifolia (M.Vahl) C.Agardh, 1817
- Comb Seaweed, Green Sea Palm and Killer Algae
(Non-native highly invasive HORIZON species)

Caulerpa racemosa (Forsskål) J.Agardh, 1873
- Sea Grapes
(Non-native highly invasive HORIZON species)

Ulvophyceae (Class) > Bryopsidales (Order) > Codiaceae (Family)

Codium adhaerens C.Agardh, 1822 - A green seaweed
Codium fragile subsp. fragile (Suringar) Hariot, 1889
- Green Sea Fingers (non-native species)

Codium tomentosum Stackhouse, 1797 - Velvet Horn
Codium vermilara (Olivi) Delle Chiaje, 1829
- A green seaweed

Ulvophyceae (Class) > Bryopsidales (Order) > Derbesiaceae (Family)

Derbesia marina (Lyngbye) Solier, 1846
- Silky Thread Weed

Ulvophyceae (Class) > Bryopsidales (Order) > Ostreobiaceae (Family)

Ostreobium quekettii Bornet & Flahault, 1889
- A green boring algae

Ulvophyceae (Class) > Cladophorales (Order) > Anadyomenaceae (Family)

Anadyomene stellata (Wulfen) C.Agardh, 1823
- Common Sea Kale (non-native species)

Ulvophyceae (Class) > Cladophorales (Order) > Cladophoraceae (Family)

Chaetomorpha linum (O.F.Müller) Kützing, 1845
- Flax Brick Weed

Chaetomorpha melagonium (F.Weber & Mohr) Kützing, 1845 - Glaucous Brick Weed
Chaetomorpha species Chyandour, Penzance, 21.05.15
- A Brick Weed

Cladophora albida (Nees) Kutzing, 1843
- Pale Green Branched Weed

Cladophora pellucida (Hudson) Kützing, 1843
- Pellucid Green Branched Weed

Cladophora rupestris (Linnaeus) Kützing, 1843
- Common Green Branched Weed or Rock Cladophora

Cladophora sericea (Hudson) Kützing, 1843
- Silky Green Branched Weed

Cladophora species (1) - A Green Branched Weed
Cladophora species (2) - A Green Branched Weed
Cladophora species (3) - A Green Branched Weed

Rhizoclonium riparium (Roth) Harvey, 1849
- Rooting Green Thread Weed

Ulvophyceae (Class) > Ulotrichales (Order) > Gomontiaceae (Family)

Monostroma grevillei (Thuret) Wittrock, 1866
- A Green seaweed

Ulvophyceae (Class) > Ulotrichales (Order) > Ulotrichaceae (Family)

Spongomorpha aeruginosa (Linnaeus) Hoek, 1963
- Spongy Weed

Spongomorpha aeruginosa (Linnaeus) Hoek, 1963
Chlorochytrium inclusum sporophyte phase
- Spongy Weed

Spongomorpha arcta (Dillwyn) Kützing, 1849
- Green Tarantula Weed or Dillwyn's Spongy Weed

Ulothrix flacca (Dillwyn) Thuret, 1863
- Flabby Shaggy Hair Weed

Ulothrix speciosa (Carmichael) Kützing, 1849
- Showy Shaggy Hair Weed

Ulvophyceae (Class) > Ulvales (Order) > Kornmanniaceae (Family)

Blidingia minima (Nägeli ex Kützing) Kylin, 1947
- Lesser Grass Kelp or Squashed Gutweed

Tellamia contorta Batters, 1895 - A Green microalgae

Ulvophyceae (Class) > Ulvales (Order) > Ulvaceae (Family)

Percursaria percursa (C.Agardh) Rosenvinge, 1893 ?
- A Green algae

Ulva clathrata (Roth) C.Agardh, 1811 - Spiky Tendrils
Ulva compressa Linnaeus, 1753 - Thread or Tape Weed
Ulva flexuosa Wulfen, 1803 - Thread or Tape Weed
Ulva intestinalis Linnaeus, 1753 - Gut Weed
Ulva lactuca Linnaeus, 1753 - Sea Lettuce
Ulva linza Linnaeus, 1753 - Doubled Ribbon Weed
Ulva prolifera O.F.Müller, 1778 - Thread or Tape Weed
Ulva rigida C.Agardh, 1823 ? - A Green seaweed

Ulva sp. bloom - Chyandour Rocks, Penzance 05.08.17.

Umbraulva dangeardii M.J.Wynne & G. Furnari formerly Umbraulva olivascens (P.J.L. Dangeard) G. Furnari, nom. inval. - A probable non-native green seaweed

Ulvophyceae (Class) > Ulvales (Order) >
Ulvellaceae (Family)

Epicladia flustrae Reinke, 1889 - An epi-endozoic
parasite of bryozoa including Flustra foliacea
and Alcyonidium hirsutum.

Ulvella setchellii P.J.L.Dangeard, 1931 ?
- An epiphyte on Osmundea pinnatifida

Objects that look like Green Seaweed
Swan Droppings / Poo

Many thanks to Professor Michael Guiry for his help in identifying some of the seaweeds featured on this page.
Michael Guiry's Seaweed Website

Other people have also provided advice about the algae on this page and numerous reference books have been used.

These include -

Seaweeds of Britain and Ireland (Seasearch) by Francis Bunker, Christine Maggs, Juliet Brodie and Anne Bunker. Published by Wild Nature Press

Volumes of Seaweeds of the British Isles by the Natural History Museum

Seaweeds by W. Braune and M. D. Guiry

Green Seaweed and Green Algae Images UK Chlorophyta