An earlier attempt to identify characteristics of Taxus that fit into a phytogeographical species concept, as recognized by Pilger, Rehder and others, has not proved satisfactory for 8-12 species that have been generally recognized in the genus. An alternative approach has been to classify morphological features of Taxus without regard to their geographical parameters. Leaf anatomical data suggest a long evolutionary history for the genus, whereas morphological differences in reproductive structures are rarely evident. Generally, species are recognized in three groups with further subdivisions based on leaf anatomical features. These are the Wallichiana Group that includes a Chinensis Subgroup, a Sumatrana Group, and a Baccata Group with T. canadensis and T. cuspidata species alliances or complexes. Currently, about 55 taxa are recognized, many of which are sympatric or allopatric in distribution, and many hybrids or intermediates are also evident. Examples of the key will be posted. It will also be placed online ( The key includes more than 100 photographs and illustrations to show comparative examples of the same taxon from different geographic regions. Included are many type specimens. The similarity of taxa from distant geographic regions and their dissimilarity within a geographical area demonstrate that the taxonomic characters applied in the present study are more meaningful than the past arbitrary phytogeographic species concepts of the genus. Nomenclatural references, descriptions, and citations of specimens will be made available in a separate publication on a taxonomic revision of the genus.

Key words: conifers, gymnosperms, Taxaceae, taxonomic key, Taxus