This poorly understood, variable taxon occurs on damp calcareous sites in the southern Interior Low Plateaus and Ridge & Valley region (Campbell & Seymour 2013). There appear to be colls. from n. Miss. (rare in loess bluffs, perhaps atypical), n. Ala., n. Ga., Tenn. and s. Ky. R. chapmanii has been much confused with palustris (within which Ch+ include chapmanii), sullivantiii and umbrosa in some treatments; see also notes under those names. It sppears closest to sullivantii (both probably being tetraploids), but it differs as follows: larger cauline leaves crenate-dentate with teeth projecting mostly 1-2 mm from sinuses (versus sharply dentate with teeth 2-5 mm); largest basal leaves up to 6-9 cm wide (versus 9-12 cm), with L/W ca. 1.5-2 (versus 1-1.5); middle to upper cauline leaves ovate-lanceolate, widest about a third from base (versus ovate-lanceolate to subrhombic, often widest just below middle); rays ca. 15-25 × 4-6 mm (versus 20-35 x 5-9 mm); paleae densely to thinly ciliate (versus thinly ciliate to eciliate). The only well-known site in Ky. is the seep with Parnassia grandiflora in CLIN near "Falls-of-76"; see colls. of M. Medley (DHL for APSC). Some other colls. need further investigation to determine if they are referable to chapmannii or just broad leaved extremes of typical fulgida (perhaps as var. acuminata). There is also an 1835 coll. of C.W. Short that appears to be this taxon, mounted with hirta at GH without locality.