This monotypic genus occurs widely in east-central states, generally in mesic to subxeric woods on slightly acid soils (pH typically 5.5-6.5); its range is similar to that of Panax quiquefolius but less extensive (K).. Common associated species in Pa, included the following trees (Zuiderveen et al. 2019): Liriodendron, Acer saccharum (both most frequent), Juglans nigra, Quercus rubra, Q alba, Carya cordiformis. Common understory species included Lindera, Parthenocissus, Arisaema triphyllum, Berberis thunbergii, Podophyllum, Bortypus, Dryopteris marginalis. There has been increasing support for treatment of Hydrastis in Hydrastidaceae (as reviewed by W). Rafinesque (1836, 2:34) described an unusually large plant in "West Kentucky" that was "over one foot high" and "three leaved" on the stem; he called this H. trifolia, but no segregates are currently recognized. Hydrastis has been much reduced by harvesting for medicinal use of its roots and rhizomes, and high deer populations can reduce its abundance (Frankland & Nelson 2003). In Ky. large patches are still found in some localities (except across most of the Bluegrass region), and these tend to recover from harvesting if the digging is not excessive. Hydrastis usually occurs in rather deep woods on mesic to subxeric sites with moderately base-rich soils, especially with a mix of sandy and limey soil parent material. Cultivation has not become widespread in Ky., but there is economic potential. Plants grow slowly, and tend to die in regular gardens; they do best with 60-70% shade on well drained organic loams with pH 5.5-6.5 (Sinclair & Catling 2001, 2004). Preliminary evidence suggests that soil disturbance and removal of old leaves by raking or burning can reduce fungal problems or other limitations to growth (see also Rock, 2000). Plants contain diverse flavonoids (especially in leaves) and isoquinoline alkaloids (especially in rhizomes), including hydrastine and its hydrolysis product hydrastinine; the latter has haemostatic properties. Antibiotic or other medicinal values of plant preparations remain somewhat controversial, but there is some scientific evidence and much anectodal evidence that the powdered rhizome can reduce oral pathogens (Hwang et al. 2003, Junio et al. 2011).