For Phryma
Barker, W.R., G.L. Nesom, P.M. Beardsley, and N.S. Fraga. 2012. A taxonomic conspectus of Phrymaceae: A narrowed circumscription for Mimulus, new and resurrected genera, and new names and combinations. Phytoneuron 2012-39: 1–60.
Cantino In Kadereit, J.W. 2004. The families and genera of vascular plants. VII. Flowering plants – Dicotyledons – Lamiales (except Acanthaceae including Avicenniaceae). Springer, Berlin. 478 pp.
Lee, N.S., T. Sang, D.J. Crawford, S.H. Yeau, S.-C. Kim. 1996. Molecular divergence between disjunct taxa in eastern Asia and eastern North America. Amer. J. Bot. 83: 1373-1378.
Nie, Z.L., H. Sun, P.M. Beardsley, R.G. Olmstead, and J. Wen. 2006. Evolution of biogeographic disjunction between eastern Asia and eastern North America in Phryma (Phrymaceae). Amer. J. Bot. 93(9): 1343-1356.
Thieret, J.W. 1972. The Phrymaceae in the southeastern United States. J. Arnold Arb. 53: 226-233.
Wagstaff, S.J., and R.G. Olmstead. 1997. Phylogeny of Labiatae and Verbenaceae inferred from rbcL sequences. Systematic Bot. 22: 165-179.
Walker, J.B. 2019. Phryma. In Flora of North America Editorial Committee. 2019. Flora of North America north of Mexico. Volume 17, Magnoliophyta: Tetrachondraceae to Orobanchaceae. Oxford Univ. Press, New York, NY. 737 pp.