In a broad sense, successful persistence in a plant community involves not only the immediate competition for resources such as light or soil nitrogen, but also processes such as effective dispersal of propagules and their successful establishment. In the longer term, successful species must also be able to accommodate changes in the environment such as climatic alterations. Although plant structure plays a significant role in phenomena such dispersal, the chapter focuses only on the role of plant architecture in the immediate competition for resources between neighboring plants.