Thonner’s analytical key to the families of flowering plants

segregated' families have now all been accounted for. We have also tried to check the many curious or aberrant genera, but have undoubtedly missed many. The keys have not become easier because of all these additions. The number of"key couplets has increased from 812 (excluding footnotes) in the 1917 edition, to 2117 in the present one. Nevertheless, they provide a useful means of identification and force students as we know from experience, to make a clear and careful analysis and logical interpretation of the various parts of the plant. We hope that all those interested through profession or hobby may be aided in a rapid identification of their material, and that we have made Franz Thonner and his works slightly better known and appreciated. We invite the user to point out errors, difficulties, and omissions. It should then be indicated in which couplets difficulties arose with a suggestion as to how they might be remedied. A representative specimen would be useful, even if only on loan. Any assistance will be acknowledged in future editions. For The Identification Of A Flowering Plant The First Step Usually Is To Discover To Which Family It Belongs. With Some Experience, The Families Commonly Encountered In One's Area Of Interest Are Soon Known, But When Dealing With Specimens From Other Places, Notably Those From The Vast And Rich Subtropics And Tropics, There Is Much Less Certainty. The Pertinent Literature Is Often Not Readily Available As It Is Often Found Only In Expensive, Rare Or Obscure Books, Or Journals, Present Only In A Few Specialized Institutes. Basically Only A Few Keys To The Families Of Flowering Plants Of The World Have Ever Been Produced, The Best Known Of Which At Present Is Hutchinson's Key To The Families Of Flowering Plants (1973); Less Well-known Are Lemee's Tableau Analytique Des Genres Monocotyledones (1941) (incl. Gymnosperms) And His Tableau Analytique Des Genres Dicotyledones (1943), And Hansen And Rahn's Determination Of Angiosperm Families By Means Of A Punched-card System (dansk Bot. Ark. 26, 1969, With Additions And Corrections In Bot. Tidsskr. 67, 1972, 152-153, And Ibid. 74 1979, 177-178). Of Note Also Are Davies And Cullen's The Identification Of Flowering Plant Families, 2nd Ed. (1979), Which, However, Deals Only With The Families Native Or Cultivated In North Temperate Regions, And Joly's Chaves De Identifi~iio Das Familias De Plantas Vasculares Que Ocorrem No Brasil, 3rd Ed. (1977), Which May Be Useful In Other Tropical Areas Too. Front Matter....Pages i-xxvi Concise Key to the Major Groupings....Pages 1-1 Key to the Families....Pages 3-197 Back Matter....Pages 198-231