Students aged between 12 and 17 in four schools (France-La Réunion, mainland France, Romania, Spain) will carry out a project turned towards an environmental issue of Europe: P.O.L.L.E.N. (Plants, Over their Life, Learning European Nature). The project is divided into four phases. Each of these phases includes teamwork in each school and a pooling during the mobility to organise an event ending the phasis: *Lecture and exhibition of posters about the biology of plants *Lecture about the relationships between plants and their environment, completed with an exhibition of photographs of plants. *Lecture about the history between plants and Men completed with the presentation of the common booklet, the testimony of the diversity of the using of plants through Europe, and a POLLEN fair with stands lead by professionals. *Lecture about the risks incurred by plants and the ways of conservation and projection of a film about local specificities: threatened species and Conservation Areas.