All plants, depending on their structure, are divided into two large groups – lower and higher.
The body of the most primitive lower plants may consist of one cell. The body of multicellular lower plants is called the thallus, or thallus (from the Greek word “tallos” – green branch). These plants have no roots, no stems, no leaves.
Lower plants do not have a complex tissue structure.
In higher plants, the body is built of various tissues and is dissected into organs – leafy shoots and roots (mosses have no roots).
Plants can be subdivided into groups (systematic units) according to similar characteristics.
The science that deals with this research is called taxonomy.
The plant kingdom is subdivided into divisions, which differ in important features (it is important, for example, how plants reproduce).