This is widespread in deep, mesic woods on fertile soils across eastern states, except on the southeastern Coastal Plain. The smaller range of giganteum is generally enclosed within the range of thalicroides (K). Some mapped records here may still be referred to giganteum; further revision is needed. Caulophyllum was relatively sensitive to excessive disturbance within the woods after settlement. In the central Bluegrass, Short (1828-9) noted: "...once abundant throughout this country, but has now almost disappeared from the more cultivated districts, and is consequently rare about Lexington, being only met with in the more secluded and unfrequented woodlands." Another genus with compound leaves in this family, Epimedium from East Asia, is widely used in horticulture, but naturalization is virtually unknown in North America (FNA 3, K, W).