The course begins with the internal (cells, tissues,etc.) and external (root, stem, leaf, etc.) organizations in plants, especially those with conducting tissues in view of their importance for man (e.g. food, lumber, medecines, etc.). A second part concerns the origin of life, evolution, classification and systematics. The last part focuses on the different lines of evolution, and reviews nonvascular and vascular plants, algae, fungi, lichens and bacteria, as well as the virusses, viroids and prions.