New insights in the recognition of the European ash species Fraxinus excelsior L. and Fraxinus angustifolia Vahl as useful tools for forest management Pierre R. Gérard, Juan F. Fernández-Manjarrés, Paola Bertolino, Jean Dufour, Christian Raquin and Nathalie Frascaria-LacosteAnn. For. Sci., 63 7 (2006) 733-738DOI: https://doi.org/10.1051/forest:2006054