Visiting the local plant nursery can be confusing these days. Public demand for native plants is increasing, yet a visit to your nearest garden store presents you with choices where you should understand the definitions before you choose a plant for your home.
Cultivar, an abbreviation of cultivated variety, is defined as from the native species, a new plant was created either by natural cross pollination, natural mutation, people cross pollinating, or genetic modification of the plant. This new plant retains many of the original plant’s characteristics but may have more appeal such as larger flowers, different colored leaves, different flower colors, better growth habit, or better disease resistance.
A nativar is a native cultivated variety, which means that it was naturally pollinated or created from native plant parents. Nativars can have the same characteristics as the native plants in that they are adapted to the same geographic region as the native species in regard to disease resistance, local weather, and local soils. However, nativars have less genetic diversity than the same native species, and the genetic changes can frequently cause changes that make the nativar unacceptable to wildlife species that depend on that specific native plant.
For both cultivars and nativars, flowers can be sterile, leaves can be a different color, or nectar could not be as available to native creatures that depend on the native plant for food, a place to lay eggs, or as food for newly hatched larvae. Many birds such as goldfinches depend on flower seeds of native plants for their specific nutrition requirements.
One example of a nativar is the different varieties of Coneflower/Echinacea that are now available to the public. The first photo shows a native coneflower. The other 3 photos are nativars.
This information from the Maryland Cooperative Extension explains the issue well:
"The question is not whether it’s morally wrong to use cultivars, but whether they are good for ecosystem health. Sterile cultivars of native plants are benign; they can’t cross-pollinate with their wild relatives, so they pose no risk to wild plant populations. When cultivars are beneficial to ecosystems, they are good. For example, plant breeders are working to create disease-resistant cultivars of native tree species that have been hit hard by non-native invasive plant pathogens. If done with care, it is possible that such cultivars could be used to intentionally spread beneficial DNA into wild plant populations and help restore those species."