[Ambrosia, Franseria, Xanthium from the Bonaparte Herbarium]

Recently, French Association for Ragweed Study (AFEDA) founders published, in French, a book "Ambrosia, ragweed, biological pollutants". This association was founded in 1982. The authors referred to Bonaparte Herbarium set up in the Université Claude-Bernard Lyon 1. This herbarium is ranking second in France and seventh in the world. There were three aims for this work: to set up, for this herbarium, a complete list of different species of Ambrosia, Franseria and their pollen grains and to study with them Xanthium whose pollen grains look like Ambrosia, to establish a chronological order for Ambrosia that were collected in Europe and in some countries of the New World, to compare some pollen grains of Ambrosia and Xanthium (scanning electronic microscope). Good state plants in spite of about a century of conservation could be selected. They were photographied and some pollens so. The consultation of this herbarium brought a better morphological knowledge of different species of Ambrosia, Franseria and Xanthium, (plants and pollen grains). The authors were able to broadcast this knowledge to scientists and interested public through their book.