Ulva (and Letterstedtia): foliaceous, flat membranous or cup-shaped or tubular, blade 2 cells thick when flat, one cell when tubular. Chloroplasts single, parietal, with one to several pyrenoids.
Eleven species on south coast.

Bryopsis: tubular, siphonous (no cross-walls), filamentous, main axes and short branches, gametes in unmodified branches.
Six species on south coast.

Cladophora and Willeella: uniseriate filamentous, multicellular, branched, axes free, erect, filaments at least 20 µm wide. Ten species on south coast (9 Cladophora and 1 Willeella). Willella has neatly pinnate (feather-like) branching.

Chaetomorpha: filamentous, unbranched, only basal cell attached or sometimes in floating mats, filaments over 100 µm diameter.
Six species on south coast.

Rhizoclonium: multicellular filaments up to 60 µm diameter, forming loose mats, filaments sometimes with rhizoidal branches.
One species on south coast.

Derbesia/ Halicystis: sporophytes siphonous, filamentous, sparsely branched, sporangia on double-walled pedicel. Halicystis stage ovoid/spherical.
Two species on south coast.

Caulerpa: siphonous, horizontal stolons with erect fronds of various shapes.
Six species on south coast.

Codium: thalli of utricles (inset) united into spongy structures of various shapes, gametangia lateral on utricles.
Sixteen species on south coast.

Pseudocodium: thalli soft, branched, core of siphons with cortex of utricles, gametangia developing from medullary siphons.
One species on south coast.

Halimeda: thalli jointed, calcified, branched, gametangia on surfaces of segments.
Two species on south coast.

Udotea: flat, stiffish (calcified) blades on stalks, thalli to ca 3cm tall, filamentous internal structure, blades with concentric growth lines.
One species on south coast.

Chamaedoris: thallus brush-like, capitulum (head) of adherent siphons borne on unbranched stipe.
Two species on south coast

Valonia: thallus of large (1-35 mm diameter) cells forming cushions a few to 20 cm in daimeter.
Two species on south coast.

Sporocladopsis: epiphytic, forming green to black velvety cushions on large algae. Comprising mat of multicellular filaments.
One species on south coast.

Blidingia: pale green tubular thalli up to 5 cm tall, walls one cell thick, chloroplasts stellate with single central pyrenoid.
One species on south coast.

Acrochaete: thallus microscopic, comprising unseriate filaments creeping in cell walls of larger algae. Cells with single parietal, reticulate chloroplast.
One species on south coast.