A simple, nonflowering, and typically aquatic plant of a large group that includes the seaweeds and many single-celled forms. Algae contain chlorophyll but lack true stems, roots, leaves, and vascular tissue.
Divisions Chlorophyta (green algae), Heterokontophyta (brown algae), and Rhodophyta (red algae); some (or all) are frequently placed in the kingdom Protista. See also blue-green algae‘That is, a simple alga like Volvox and a complex metazoan like an octopus both occupy the same sublevel.’
- ‘It is a blue-green alga, a primitive plant of the same class as seaweeds or the green slime seen on rocks and jetties when uncovered by the sea at low tide.’
- ‘The phenomenon was first described in a red alga and a green alga more than 30 years ago.’
- ‘Most of the lichen is composed of fungal filaments, but living among the filaments are algal cells, usually from a green alga or a cyanobacterium.’
- ‘The classical examples of symbiosis are the lichens, in which a fungus is associated with an alga or a cyanobacterium.’
Mid 16th century from Latin, ‘seaweed’.