This key to the woody plants occurring in Austria includes both native species and the most common alien species planted in garden and parks. The list of native species was easily obtained from FISCHER et al. (2008), while for alien species we had to rely on our experience in Eastern and Southwestern Austria and on works centered on cultivated species in the temperate zone of Central Europe (MEYER et al. 1994, ROHLOFF & BÄRTELS 1996, C. SCHNEIDER 1904-06). In order to assess the commoness/rarity of alien species in cultivation, we also consulted the online catalogues of important commercial companies in Austria (e.g. Praskac, Ecker-Eckhofen, Loidl). The result was a list of 595 infrageneric taxa , including both low shrubs and tall trees. A first version of the key was produced in the early spring of 2011, using the software FRIDA (MARTELLOS 2010, NIMIS & VIGNES LEBBE 2010) and the corresponding database of Project Dryades (University of Trieste). That key was thoroughly tested both on living material in the Botanical Garden of the University of Graz and on specimens of the GZU Herbarium, which resulted in several proposals of modifications, sent back to Trieste and implemented there. For cultivated alien plants the we consulted recent floras of the temperate part of the Northern Hemisphere (Flora of China, Flora of North America), sometimes even floras of narrow areas (e.g. RHOADS & BLOCK 2000). The present key does not include the myriad of cultivars in genera such as Chamaecyparis, Cupressus, Thuja, Juniperus, Taxus. In most cases it brings to a species, but in form-rich and difficult genera it stops at the genus level (e.g. alien Rhododendron, Cotoneaster, Malus, Rosa, Rubus). We would be grateful for any feedback concerning errors or other problems in the key.

Referencesr
FISCHER M.A., OSWALD K. & ADLER W. 2008 - Exkursionsflora für Österreich, Liechtenstein, und Südtirol. 3. Aufl.- Linz: Land Oberösterreich, Biologiezentrum der Oberösterr. Landesmuseen.
Flora of China Editorial Committee, eds. 1999+ - Flora of China. – Missouri Botanical Garden.
Flora of North America Editorial Committee, eds. 1993+ - Flora of North America North of Mexico. 16+ vols. New York and Oxford.
MEYER F.H., HECKER U., HÖSTER H.R & SCHROEDER F.-G. 1994 - Jost Fitschen. Gehölzflora: ein Buch zum Bestimmen der in Mitteleuropa wachsenden und angepflanzten Bäume und Sträucher. 10. Überarb. Aufl. – Quelle & Meyer. Heidelberg, Wiesbaden.
MARTELLOS S. 2010 - Multi-authored interactive identification keys: The FRIDA (FRiendly IDentificAtion) package. Taxon, 59, 3: 922-929.
NIMIS P.L. & VIGNES LEBBE R. (eds.) 2010 - Tools for Identifying Biodiversity: Progress and Problems – ISBN 978-88-8303-295-0. EUT, 455 pp.
RHOADS A.F. & BLOCK T.A. 2000 - The plants of Pennsylvania: an illustrated manual. (with illustrations by A. Anisko. – University of Pennsylvania Press. Philadelphia.
ROLOFF A. & BÄRTELS A. 1996 - Gartenflora Band 1 - Gehölze. – E. Ulmer, Stuttgart.
SCHNEIDER C. K. 1904-06 - Illustriertes Handbuch der Laubholzkunde. Charakteristik der in Mitteleuropa heimischen im Freien angepflanzten angiospermen Gehölz-Arten und Formen mit Ausschluss der Bambuseen und Kakteen. – G. Fischer, Jena.