As you step into nature — whether by a shimmering lake or in the mottled shade of an old house — you'll encounter green life all around.Over 500,000 species of green plants are known in the biosphere. They differ in form and habitat, and can be divided into four major groups: algae, bryophytes (mosses), ferns, and seed plants.

1. From Green Film to Bio-Indicator: The Art of Adaptation

The green film on aquarium walls is made of simple algae — they lack true roots, stems, and leaves, absorbing water across their entire surface. The "green carpet" in damp corners, on the other hand, consists of mosses. Though tiny, they have sensitive physiological traits. Since their leaves are only one cell thick, they are highly sensitive to toxic gases and are often used asindicator plants.

2. The Ark of Life: Seeds and the Embryo

To survive on the ever-changing land, plants evolved seeds.The embryo is the young plant, containing all the blueprints for future life. In studying higher plants, we find:Plants whose seeds have an embryo with two cotyledons are called dicotyledons (dicots).