This widespread variable species (2n = 38, 59, 60) grows in seasonally wet calcareous open areas across cool temperate regions of North America, but there is much disjunction between major populations (FNA 23, K). In Ky. it is locally abundant but restricted to few regions, especially in glades of the Nolin River and lower Salt River watersheds. In Tenn. it is known only from the Nashville Basin (Ch). More searching is needed; several records mapped here remain unconfirmed, based on colls. that have not been located or checked (including data of NP). Plants are generally short and easily overlooked.