Habitat-selection concepts have rarely been explicitly used for plants, perhaps because the majority of them are immobile. For plants, habitat selection results from evolutionary adjustment of species to environmental factors so that the species functions better in some habitats than in others. Habitat choice refers to the ability of a plant to disperse, in space or time, to preferred patches. Habitat specialization means that a species performs best in a small subset of patches in a given location. The modular structure of plants and their growth response to the patterns of resource availability allows them to occupy large areas, exposing them to spatial and temporal heterogeneity. Modular structure, to a large extent, determines the options available, as well as the constraints, for plants choosing habitats. Choice, however, may be made by the habitat rather than by the plant. That is, the characteristics of the habitat determine which species of the plants that disperse into the habitat become establis...