Why are algae considered plants?

Algae are NOT considered plants. Instead algae are considered protists in the old classification of eukaryotes (not bacteria). Alga are actually three main unrelated stock, the Cabozoa, Chromalveolata and Archaeaplastida (plants). There's also the (not algae) blue-green algae, which is a bacteria. read more

First of all, algae may be unicellular, colonial, or multi-cellular. Plants, on the other hand, are only multi-cellular. Holdfasts, stapes and blades compose multi-cellular algae. In comparison, plants have roots, stems, leaves, flowers, fruits, seeds and cones. read more

Though many types of algae are organisms that produce their own food through the process of photosynthesis, they are not classified as plants. In fact, algae are classified outside of the plant kingdom, in a group of their own known as the protista kingdom. read more

Algae are able to photosynthesize, a key characteristic of plants, but lack true roots, stems, or leaves so are not considered plants. The two main groups of algae are prokaryotes (no nucleus) including the blue-green algae; and eukaryotes (contain a nucleus). read more

Plants and algae are both photosynthetic. Both are also considered eukaryotes, consisting of cells with specialized components. They both also have the same life cycle called alternation of generations. read more