In this section
Colonial chlorophyte with spherical to ovoid cells in rows set in mucilage, usually creating colonies resembling a flat sheet of loosely-connected ribbons. Another species has cell walls in two halves, and does not form a sheet, but this is so far unknown from New Zealand. Chloroplasts green, lobed, always lacking pyrenoids. This genus was first described from New Zealand, but is now known to be world wide.