1 Introduction.- A. What is a Tree?.- I. Definitions.- II. Tree Making.- III. Apical Meristems and Tree Construction.- 1. Trees Built by One Meristem.- 2. Trees with Modular Construction.- 3. Trees with Trunk-Branch Differentiation.- 4. Trees with Changes in Orientation of Axes.- B. The Botanical World of the Tropics.- I. Distribution and Size of Flowering Plant Families.- II. Tropical Floras as Tree Floras.- III. Floristic Richness in Limited Areas.- IV. Geographic Locations.- V. Climate and Tree Growth in the Tropics.- 2 Elements of Tree Architecture.- A. The Initiation of the Tree.- I. Seedling Morphology.- II. Juvenility and Phases of Development.- B. Apical Meristems and Buds.- I. Terminal Buds.- II. Bud Composition.- III. Lateral Buds.- IV. Secondary Bud Complexes.- C. Extension Growth in Tropical Trees.- I. Introductory Remarks.- II. Rhythmic Growth.- 1. Rhythmic Growth in Hevea.- 2. Preformation and Neoformation.- 3. Further Examples of Rhythmic Growth.- III. Continuous Growth.- 1. Palms.- 2. A Dicotyledon.- D. Phyllotaxis and Shoot Symmetry.- I. Primary Orientation.- II. Secondary Orientation.- E. Branching: Dynamics.- I. Branch Order Terminology.- II. Syllepsis and Prolepsis.- 1. Definitions and Descriptions.- 2. Historical Usage of the Terms.- 3. Apical Dominance.- III. Continuous and Diffuse (Intermittent) Branching.- F. Branch Polymorphism: Long Shoots.- I. Orthotropy and Plagiotropy.- 1. Strict Orthotropy of Trunk Axes.- 2. Orthotropic Branches.- 3. Plagiotropic Branches (Reversible).- 4. Plagiotropic Branches (Nonreversible).- 5. Phyllomorphic Branches.- II. Branch Complexes and Sympodial Growth.- III. Plagiotropy and Syllepsis.- IV. Plagiotropy in Monocotyledons.- G. Branch Polymorphism: Short Shoots.- I. In Dicotyledons.- II. In Monocotyledons.- H. Abscission.- I. Inflorescence.- I. Flowering and Shoot Construction.- II. Continuous Flowering.- III. Cauliflory.- IV. Floral Phenology.- J. Radial Growth: Conifers and Dicotyledons.- I. Growth Rings.- IIlCi