Algae

Algae (/ˈældʒiː/ or /ˈælɡiː/; singular alga /ˈælɡə/) is an informal term for a large, diverse group of eukaryotes that are not necessarily closely related and are thus polyphyletic. Included organisms range from unicellular genera, such as Chlorella and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga that may grow up to 50 meters in length. Most are aquatic and autotrophic and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem, that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the Charophyta, a division of green algae that includes, for example, Spirogyra and the stoneworts.

There is no generally accepted definition of algae. One definition is that algae "have chlorophyll as their primary photosynthetic pigment and lack a sterile covering of cells around their reproductive cells". Some authors exclude all prokaryotes and thus do not consider cyanobacteria (blue-green algae) as algae.

Algae (disambiguation)

Algae are a type of Protist.

Algae may also refer to:

See also