It is always best to source plants and seeds from as near to your growing region as possible. Local ecotypes are understood to always perform better as they are specifically adapted to our area.
MAIL ORDER NATIVES - https://www.mailordernatives.com
NATIVE PLANT DATABASES & INFO
BONAP (The Biota of North America Program): http://www.bonap.org, search any plant genus to see native range
USDA Plants Database: https://plants.sc.egov.usda.gov/java/
Louisiana Native Plant Society: Databases, links and more https://www.lnps.org/references