The study enumerated 19,154 trees represented by 149 species in 45 botanical families, with clear domination by a small number of popular ones, and substantial contribution to diversity by those with low frequencies. Broadleaf, evergreen, exotic and young trees prevail over other growth forms. Changes in species preference over the years and earnest attempts recently to introduce hitherto untried species were detected. Species composition was evaluated according to five frequency groups, with respect to cultivation history, performance, suitability for roadside habitats, and possible origins especially of the occasional and rare species. The implications of the database and its interpretations to management and planning of amenity vegetation were explored. Copyright © 1996 Taylor & Francis Group, LLC.