This is a list of green seaweeds recorded from the oceans bordering the Cape Peninsula in South Africa from Melkbosstrand on the West Coast to Cape Hangklip on the South Coast. This list comprises locally used common names, scientific names with author citation and recorded ranges. Ranges specified may not be the entire known range for the species, but should include the known range within the waters surrounding the Republic of South Africa.

Green seaweed refers to thousands of species of macroscopic, multicellular, marine algae in the taxon Chlorophyta

The marine ecology is unusually varied for an area of this size, as a result of the meeting of two major oceanic water masses near Cape Point, and the area extends into two coastal marine bioregions. The ecology of the west or "Atlantic Seaboard" side of the Cape Peninsula is noticeably different in character and biodiversity to that of the east, or "False Bay" side. Both sides are classified as temperate waters, but there is a significant difference in average temperature, with the Atlantic side being noticeably colder on average.

List ordering and taxonomy complies where possible with the current usage in Algaebase, and may differ from the cited source, as listed citations are primarily for range or existence of records for the region. Sub-taxa within any given taxon are arranged alphabetically as a general rule. Details of each species may be available through the relevant internal links. Synonyms may be listed where useful.

Class: Bryopsidophyceae

Order: Bryopsidales

Family: Bryopsidaceae

Bryopsis africana Areschoug, 1851,M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=21218; searched on 26 February 2012 (Probably along the whole of the west Cape coast) Bryopsis eckloniae Stegenga, Bolton & Anderson 1997,Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=3440; searched on 26 February 2012 (Muizenberg, endemic) Bryopsis hypnoides Lamouroux, 1809c, (False Bay) Sea moss, Bryopsis myosuroides Kützing, 1856, (TMNPMPA). Bryopsis plumosa (Hudson 1778) C. Agardh 1823, l syn. Ulva plumosa Hudson 1778,M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=10; searched on 26 February 2012 (False Bay and eastward)

Family: Caulerpaceae Caulerpa bartoniae G. Murray, 1896,M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=21260; searched on 26 February 2012 (Rare in Western Cape, Cape Hangklip and Muizenberg. Mainly from south coast. endemic) Strap caulerpa Caulerpa filiformis (Suhr) Hering 1841, syn.Amphibolis filiformis Suhr 1834, Himandactylius filiformis (Suhr) Trevisan 1849,Wendy Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=1137; searched on 26 February 2012 (False Bay to northern KwaZulu-Natal)Coppejans, E., Leliaert, F and Verbruggen, H. in De Clerck, O., Bolton, J.J., Anderson, R. J. & Coppejans, E. 2005. Guide to the Seaweeds of KwazZulu-Natal. Scripta Botanica Belgica Volume 33. Joint publication of: National Botanical gardens of Belgium, VLIZ Flanders Marine Institute and Flemish Community. Feathery caulerpa Caulerpa holmesiana G. Murray, 1891, (Mainly a south coast species. the westernmost records at Cape of Good Hope, endemic)

Family: Codiaceae Duthie's upright codium Codium duthieae Silva in Silva & Womersley, 1956,Wendy Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=3432; searched on 26 February 2012 (Mainly a south and east coast species, westwards as far as Langebaan lagoon.)(From Namibia along the entire South African coast) Fragile upright codium Codium fragile subsp. fragile (Suringar) Hariot 1889, syn Codium fragile (Suringar) Hariot subsp. capense Silva 1959a, Acanthocodium fragile Suringar 1867, (Whole of Cape west coast and most of Namibia, Eastward as far as Robberg, Plettenberg Bay) Codium isaacii Silva, 1959a, (Namibia to Cape Peninsula, endemic) Lucas' codium Codium lucasii Setchell subsp. capense Silva 1959a,Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=3435; searched on 27 February 2012 (Strand, False Bay to southern Mozambique) Codium papenfussii Silva, 1959a,M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=3436; searched on 27 February 2012 (West coast of Cape Peninsula to southern KwaZulu-Natal, single specimen from Sodwana Bay, endemic) Flat-lobed codium Codium platylobium Areschoug 1854, (False Bay to mouth of Mtwalume river in KwaZulu-Natal) Stephens' codium Codium stephensiae Dickinson 1932, (St Helena Bay to Transkei, endemic)

Family: Derbesiaceae

Derbesia hollenbergii Taylor 1945, (Muizenberg and Strandfontein, False Bay, and Eastern Cape and Transkei) Derbesia marina (Lyngbye) Solier 1846, syn. Vaucheria marina Lyngbye 1819, (Muizenberg, False Bay, and Eastern Cape and Transkei)

Family: Udoteaceae Chlorodesmis sp. indet (Oudekraal, Cape Peninsula, endemic)

Class: Chlorophyceae

Order: Chaetophorales

Family: Chaetophoraceae Acrochaete sp. indet (Glencairn (False Bay) and De Hoop Nature Reserve)

Family: Chroolepidaceae Sporocladopsis novae-zelandiae Chapman, 1949 (Yzerfonten to East London)

Class: Charophyceae

Order: Charales

Family: Characeae Foxtail stonewart, Lamprothamnium papulosum (K.Wallroth) J.Groves, 1916 (TMNPMPA)

Class: Ulvophyceae

Order: Cladophorales

Family: Cladophoraceae Chaetomorpha aerea (Dillwyn) Kützing 1849, syn. Conferva aerea Dillwyn 1806, Chloronitum aerea (Dillwyn) Gaillon 1828, (False Bay to Cape Agulhas) Hair weed Chaetomorpha linum (O.F.Müller) Kützing 1845, syn. Conferva linum O.F.Müller 1778, Lychaete linum (O.F.Müller) Areschoug 1851, (Kalk Bay and Simon's Town harbours) Robust hair-weed Chaetomorpha robusta (Areschoug) Papenfuss 1940, syn. Lychaete robusta Areschoug 1851,Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=3424; searched on 27 February 2012 (Namibia to Hermanus) Chaetomorpha sp. indet, (Clovelly, False Bay) Cape cladophora Cladophora capensis (C.Agardh) De Toni 1889, syn. Conferva capensis C.Agardh 1824, (Namibia to southern Cape Peninsula) Turf cladophora Cladophora contexta Levring 1938, (Olifantsbos to Lüderitz) Cladophora dalmatica Kuetzing 1843, (Glencairn, False Bay) Blue whip cladophora Cladophora flagelliformis (Suhr) Kützing 1849, syn. Conferva flagelliformis Suhr 1840, Lychaete flagelliformis (Suhr) Areschoug 1851, (Brandfontein to Namibia) Cladophora isaacii Simons 1960, (Port Nolloth to Cape Hangklip) Cladophora mirabilis (C.Agardh) Rabenhorst in Hohenacker 1852, syn. Conferva mirabilis C.Agardh 1820, (Cape Hangklip to Cape Fria, Namibia) Cladophora radiosa (Suhr) Kützing 1889, syn. Conferva radiosa Suhr 1834, (Table Bay eastwards to Cape Morgan) Cladophora sericia (Hudson) Kützing 1843, syn. Conferva sericea Hudson 1762, Chloronitum sericeum (Hudson) Gallion 1928, (Cape Peninsula north to Melkbosstrand, east to De Hoop nature reserve) Cladophora sp. indet. (Clovelly to Buffels Bay, Cape Peninsula) Rhizoclonium implexum (Dillwyn) Kützing 1845, SYN. Conferva implexa Dillwyn 1809, Rhizoclonium riparium var. implexum (Dillwyn) Rosenvinge 1893, (Kraalbaai, Langebaan lagoon and Clovelly, Cape Peninsula)

Order: Ulotrichales

Family: Ulotrichaceae Ulothrix flacca (Dillwyn) Thuret in Le Jolis 1863, syn. Conferva flacca Dillwyn 1805, Lyngbya flacca (Dillwyn) Harvey 1849,M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=208; searched on 27 February 2012 (Cape Peninsula and False Bay)Stegenga, H., Bolton, J.J., & Anderson, R.J. 1997. Seaweeds of the South African West Coast. Contributions from the Bolus Herbarium, University of Cape Town. Ulothrix speciosa (Carmichael) Kützing 1849, syn Ulothrix zonata var. speciosa (Carmichael) Stockmayer, Lyngbya speciosa Carmichael 1833, Hormotrichum speciosum (Carmichael) P.L.Crouan & H.M.Crouan 1852, Urospora speciosa (Carmichael) Leblond ex G.Hamel 1931, (Known from a single collection at Kalk Bay)

Order: Ulvales

Family: Ulvaceae Blidingia minima (Nägeli ex Kützing) Kylin 1947, syn. Enteromorpha minima Nägeli ex Kützing 1849, Enteromorpha compressa var. minima (Nägeli ex Hauck) Hamel 1931, Enteromorpha nana var. minima (Nägeli ex Hauck) Sjøstedt 1939,M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=33; searched on 27 February 2012 (Kraalbaai, Langebaan lagoon to False Bay, and Eastern Cape) Chloropelta caespitosa Tanner 1980, (Kalk Bay and Cape Hangklip) Enteromorpha atroviridis (Levring) M.J.Wynne 1986, syn. Ulva atroviridis Levring 1938, (Namibia to Oudekraal, Cape Peninsula) Percursaria percursa (C.Agardh) Rosenvinge 1893, syn. Zignoa percursa (C.Agardh) Trevisan, Conferva percursa C.Agardh 1817, Enteromorpha percursa (C.Agardh) J.Agardh 1842, (Cape Peninsula – Glencairn, Scarborough, Mouille Point) Tangleweed, Ulva clathrata (Roth) C.Agardh, 1811, (TMNPMPA), Ulva flexuosa Wulfen 1803, syn. Enteromorpha flexuosa (Wulfen) J.Agardh 1883,Wendy Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=12999; searched on 27 February 2012 (Muizenberg and Dalebrook, False Bay and Eastern Cape) Green sea intestines, Ulva intestinalis Linnaeus 1753, syn. Conferva intestinalis (Linnaeus) Roth 1797, Tetraspora intestinalis (Linnaeus) Desvaux 1818, Scytosiphon intestinalis (Linnaeus) Lyngbye 1819, Enteromorpha intestinalis (Linnaeus) Nees 1820, Fistularia intestinalis (Linnaeus) Greville 1824, Solenia intestinalis (Linnaeus) C.Agardh 1824, Ilea intestinalis (Linnaeus) Leiblein 1827, Hydrosolen intestinalis (Linnaeus) Martius 1833, Ulva enteromorpha var. intestinalis (Linnaeus) Le Jolis 1863, Ulva bulbosa var. intestinalis (Linnaeus) Hariot 1889, Enteromorpha compressa var. intestinalis (Linnaeus) Hamel 1931,M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=12904; searched on 27 February 2012 (Widespread on west and south coasts, along entire South African coast) Ulva lactuca Linnaeus 1753, syn. Phyllona lactuca (Linnaeus) F.H.Wiggers 1780, Ulva fasciata Delile 1813,M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org/search/species/detail/?species_id=39; searched on 27 February 2012 (Saldanha Bay, False Bay eastwards into Mozambique)