A phytogeographical analysis of leaf character data will be presented to show that Taxus is least variable in North America and NW Himalayas, and most diverse in SW China. Characters include the number of cells across a marginal zone without papillae, and number of stomata rows/band. Leaf characteristics will be discussed for three species groups typified by T. baccata, T. wallichiana, and T sumatrana, and their subdivisions. Most European specimens have a baccata type (8-10 stomata rows/band bordered by a marginal zone of 4-7 smooth cells followed by 7-22 papillose cells), and less often a canadensis type (4-9 stomata rows/band bordered by 8-24 smooth cells and 0-12 papillose cells); the latter includes a cuspidata subtype that differs by papillose cell walls. Specimens from E Asia have the canadensis and cuspidata types, but often with more stomata, which range from 7-13(-16) rows/band. Northwest Himalayan specimens have the baccata type with 5-9 stomata rows/band, and show less variation in leaf length and phyllotaxy. All three types occur in the Caucasus Mountains, but most specimens there appear similar to those in Europe. From the E Himalayas to SW China, and in North America, occurs the Wallichiana Group. Its leaves usually have a uniformly papillose undersurface with a relatively narrow marginal border of smooth cells, 0-7 (-10) cells across. The epidermal cells are distinctly angular in transverse sections, and stomata show geographical differences, 7-21 rows/band in Asia, and 4-11 rows/band in North America. A Chinensis Subgroup, mostly in central China, Indonesia and Philippines, differs by rounded epidermal cells (x-sect.) that are sometimes less papillose on the ventral midrib. The Sumatrana Group, which is common in SE China, especially below 2,000 m, has a broad margin of cells bordering stomata bands, from 8-36 cells across, and often a truncate midrib.

Key words: leaf anatomy, leaf morphology and taxonomy of Taxus, phytogeography, Taxaceae