"Clematis texensis". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014. Retrieved 15 April 2018.
USDA, NRCS (n.d.). "Clematis texensis". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 20 April 2018.