So many angles and issues, this is only a beginning.
Each of these has strengths and weaknesses. Most include non-natives but allow you to filter to select only natives, but even then, they are not very precise about native ranges.
These can help you figure out if a plant you are considering is native to your state or region.
Native plant societies offer hordes of info on their websites, including lists of growers who specialize in native plants
The other side of the coin is those troublesome invasive exotic plants.
But if you have a suggestion, please pass it along.