Native plants are plants indigenous to a given area in geologic time. This includes plants that have developed, occur naturally, or existed for many years in an area (trees, flowers, grasses, and other plants).
Some native plants have adapted to very limited, unusual environments or very harsh climates or exceptional soil conditions. Although some types of plants for these reasons exist only within a very limited range (endemism), others can live in diverse areas or by adaptation to different surroundings. Research has found that insects depend on native plants.
An alternative but potentially conflicting usage is to describe plants (and animals) that are indigenous to a geographical area, even if they are known to have self-introduced in historical times such as the silvereye (Zosterops lateralis) of New Zealand, which was first recorded in the 19th century.
An ecosystem consists of interactions of plants, animals, and microorganisms with their physical (such as soil conditions and processes) and climatic conditions.
Native plants form a part of a cooperative environment, or plant community, where several species or environments have developed to support them. That could be a case if a plant exists because a certain animal pollinates the plant and that animal exists because it relies on the pollen as a source of food. Some native plants rely on natural conditions, such as occasional wildfires, to release their seeds or to provide a fertile environment in which their seedlings can become established.
As societies move plants or introduce them to new locations for cultivation as crops or ornamentals (or transport them by accident)(see 'Human impact on the environment'), some of them may become invasive species, damaging native plant communities. Besides ecological damage, these species can also damage agriculture, infrastructure, and cultural assets. Government agencies and environmental groups are directing increasing resources to addressing these species and their potential interactions with climate change. Non-native species can have profound effects on ecosystems by changing ecosystem structure, function, species abundance, and community composition.
When restoration projects are undertaken to restore a native ecological system disturbed by economic development or other events, they often are historically inaccurate and incomplete, pay little or no attention to ecotype accuracy or type conversions.They fail to restore the original ecological system by overlooking the basics of remediation: attention paid to the historical distribution of native species is a crucial first step to ensure the ecological integrity of the project. To prevent erosion of the recontoured sand dunes at the western edge of the Los Angeles International Airport in 1975, landscapers stabilized the backdunes with a “natural” seed mix (Mattoni 1989a). Unfortunately, the seed mix was representative of coastal sage scrub, an exogenous plant community, instead of the native dune scrub community. As a result, the El Segundo blue butterfly (Euphilotes battoides allyni) became an endangered species. The El Segundo Blue butterfly population, which had once extended over 3200 acres along the coastal dunes from to Ocean Park to Malaga cove in Palos Verdes, began to recover when the invasive California buckwheat (Eriogonum fasciculatum) was uprooted so that the butterflies' original native plant host, the dune buckwheat (Eriogonum parvifolium), could regain some of its lost habitat.
Humans, migratory birds, ocean currents, etc. can introduce species that have never met in their evolutionary history, on varying time scales ranging from days to decades (Long, 1981; Vermeij, 1991). Humans are moving species across the globe at an unprecedented rate. Those working to address invasive species view this as an increased risk to indigenous species.
The term "nativar" is becoming widely accepted as cultivars of native plants. The use of nativars is a widely disputed practice among native plant activists.
Native plant proponents, such as Sara Stein, and native plant organizations, such as Wild Ones, the Native Plant Society of Oregon, the New England Wildflower Society, the North American Native Plant Society, the California Native Plant Society, and Lady Bird Johnson Wildflower Center  also encourage gardeners to use earth-friendly gardening practices, especially in public spaces. The identification of local plant communities provides a basis for their work.