Phycology (or algology) is the study of
algae. Algae are
eukaryotic,
photosynthetic organisms which usually live in an aquatic environment. They are distinguished from the
plant kingdom by their lack of true
roots and
leaves. They may be microscopic and single-celled or very large and
multicellular. Algae are important as they are the primary producers for many of the world's
ecosystems.