Polygala ambigua Nutt.

POWO follows these authorities in synonymising this name:

• Flora of North America Editorial Committee (2021). Flora of North America North of Mexico 10: 1-456. Oxford University Press, New York, Oxford. [Cited as Polygala verticillata.]

This name was accepted following an alternative taxonomy by these authorities:

• Bailey, C. & al. (2015). Guide to the Vascular Plants of Tennessee: 1-813. University of Tennessee press. [Cited as Polygala ambigua.]
• Gilman, A.V. (2015). New flora of Vermont. Memoirs of the New York Botanical Garden 110: 1-614. [Cited as Polygala ambigua.]
• Iwatsuki, K., Boufford, D.E. & Ohba, H. (eds.) (1999). Flora of Japan IIc: 1-328. Kodansha Ltd., Tokyo. [Cited as Polygala ambigua.]
• Jones, R.L. (2005). Plant life of Kentucky. An illustrated guide to the vascular flora: 1-833. The universitry press of Kentucky. [Cited as Polygala ambigua.]
• Kral, R., Diamond, A.R., Ginzbarg, S.L., Hansen, C.J., Haynes, R.R., Keener, B.R., Lelong, M.G., Spaulding, D.D. & Woods, M. (2011). Annotated checklist of the vascular plants of Alabama: 1-112. Botanical reseach institute of Texas. [Cited as Polygala ambigua.]
• Mohlenbrock, R.H. (2014). Vascular Flora of Illinois. A Field Guide, ed. 4: 1-536. Southern Illinois University Press, Carbondale. [Cited as Polygala ambigua.]