Green algae are organisms that belong to the phylum Chlorophycota of the kingdom Protista,
a large group of marine and freshwater algae.
Chlorophytes have several features that make them more like green plants
than ordinary algae: they have cup-shaped chloroplasts that contain photosynthetic pigments similar
to those in higher plants (chlorophylls a and b, as well as the secondary pigments carotenes,
lutein, and zeaxanthin) and have a green color; they have cell walls made
of cellulose; and they store food in the
form of starch. Some produce cells with flagella at some stage in their lives. Green algae range in size from microscopic,
single-cell types (some with flagella) to large complex seaweeds.
|The green alga Caulerpa taxifolia with feather-like
branches. The leaf is 5–65 cm in length. Photo: NOAA