This is NOT the exotic wisteria species that has escaped to smother much of the roadside throughout the south, competing with Lonicera japonica for the title of the most invasive and worst vine. That thug is Wisteria floribunda (Japanese wisteria). Rather Wisteria frutescens ’Amethyst Falls’ is an American native species, a selection found in the northwest corner of SC and introduced by Head-Lee Nursery. It flowers as a very young plant with slightly fragrant blooms well after any chance of frost. Give it lots of sun. It usually reblooms in late spring. Vigorous but again, not invasive. Deciduous, for sun in zones 5-9.
I rarely see Chinese wisteria (Wisteria sinensis) offered except in specialty catalogs (we occasionally offer one). It’s not as rampant as Japanese wisteria but still requires a gardener to stay alert and control it. Interesting ID tidbit: our American and the Chinese species twine anti-clockwise (looking from above) while the thuggish Japanese species twines clockwise. Mount your ladder and ID your plant.