"The following native plant lists are intended as a beginning reference, and not as a shopping list for your next project. Every State has various natural regions due to climate and geological variation over time. The vegetation of these regions has evolved uniquely to each region. What grows in the southwest part of your State might be impossible to grow in the northeast, and so on. What grows at one elevation will be different from another. What grows on the north slope will look different from the south slope. And what grows on dry sand will be different from wet sand. Using a plant hardiness zone map will not help you make native plant species decisions. Using a natural vegetation map will help you match plant species to the environment to which they are adapted. The Natural Heritage Program, Native Plant Society, and /or The Nature Conservancy in your State can be of further help. Some universities specialize in native plants.
The native trees, shrubs, grasses, forbs, and vines on your State's list are common to your State, but not every region within the State. Not all are commercially available, but should be considered for propagation. Please use resources to further fine tune your list, in terms of desirable roadside characteristics: locally common, early successional, low-growing, seasonal, deep or fibrous-rooted, perennial, drought-resistant, noninvasive, available, affordable and aesthetically pleasing. In other words, to be successful you need to know as much about each species' life history and your objectives as possible. This knowledge will help you match the most appropriate plants to each project."
Source: United States Department of Transportation - Federal Highway Administration