This largely Appalachian and Ozarkian taxon is close to C. pubescens (see notes under that name) and to C. parviflorum var. makasin (Farw.) Sheviak of northeastern fens. These taxa are often combined to various degrees (Cr, FNA 26, W), but typical parviflorum appears generally distinct in Ky. It grows here in somewhat mesic woods on well-drained acid soils, often at the upper edge of Tsuga groves. Several records are not verifiable but historically important, such as sight records of B. Gm noted in 1914: "A second species [as well as pubescens], also occurring in Kentucky, with a small flower, is sold to pharmacists for the same [medicinal] purpose." C. parviflorum usually occurs with single plants or small groups, which should not be collected. C. parviflorum (sensu stricto) differs from pubescens as follows (FNA 26, W): flowers smaller, the lip 22-34 mm long (versus 35-54 mm in pubescens), with sepals and petals densely, minutely spotted dark reddish brown or "madder" (versus unmarked, spotted, striped or reticulate with same color but less uniformly dark).