Goldthread (Coptis trifolia) is an herbaceous understory plant that grows in wet areas of coniferous forests. It occurs from western Greenland throughout much of the northern United States and Canada and into eastern Russia and northern Japan. Due to overharvest for use as a medicine to treat gastrointestinal disorders and sores of the mouth, it was once rare in New England, but populations have subsequently recovered. Due to its widespread distribution and the limited market for medicinal applications, the species is listed as Least Concern.

Goldthread (Coptis trifolia) occurs over a large area within North America and eastern Asia at elevations ranging from 0 to 1,500 metres (Flora of North America Editorial Committee (FNA) 1997). Its range includes northeastern portions of the United States ranging from Minnesota to Maine and as far south as North Carolina (USDA, NRCS 2018). It has also been reported in Alaska, Oregon, and Washington (NatureServe 2018). In Canada, the species occurs in all provinces except Yukon and Northern Territories (VASCAN 2018). Outside North America, the species occurs in Greenland, Japan, and eastern Russia (Kamchatka, Khabarovsk, Magadan, Primorye, Sakhalin, and Yakutia) (Board of Trustees, RBG Kew 2018). Populations in eastern North America and Greenland belong to the subspecies C. trifolia subsp. groenlandica while those in Asia and western North America belong to the subspecies C. trifolia subsp. trifolia (Flora of North America Editorial Committee (FNA) 1997).

Though no reliable population figures are available, the species is noted to be frequent in the northern boreal portions of its range (NatureServe 2018). Given the large range of the species it is unlikely to meet thresholds for threatened status.

Goldthread is a low growing woodland perennial. It produces a single leafless stalk from which a single flower with white sepals grows (Lady Bird Johnson Wildflower Center 2018). It produces bright yellow to orange rhizomes from which the common name (Goldthread) is derived (Flora of North America Editorial Committee 1997). The species is most commonly found in wet areas (seeps, riparian areas, and depressions) within coniferous forests (NatureServe 2018).

Though it may impact subpopulations, harvest for medicinal applications occurs at a low level and is unlikely to impact the global population (NatureServe 2018).

Goldthread has been used by Abnaki, Algonquin, Iroquois, Malecite, Micmac, Mohegan, Ojibwa, and Potawatomi for a variety of medicinal purposes. Notable among these uses is a common trend indicating the herb for treatment of cold, cough, gastrointestinal problems, toothache, and canker sores (Moerman 2018). In addition, its roots have been used as a yellow dye by the Chippewa, Ojibwa, and Potawatomi. European colonists in the 18^th and 19^th centuries used Goldthread to treat stomach conditions and sores of the mouth. Its popularity was so great that populations had declined in New England due to overharvest (Bergner 1996). Herbalists substituted Goldenseal (Hydrastis canadensis) for Goldthread in the early 19^th century due to scarcity. Goldenseal is now threatened though Goldthread populations are said to have rebounded. Herbalists indicate the rhizome for treatment of digestive disorders, parasite infections, and psoriasis (WebMD 2018).

Though abundant globally, the species is uncommon in southern parts of its range. It is listed as Endangered in Maryland and Sensitive in Washington (USDA, NRCS 2018). Throughout its range it occurs in at least 13 and possibly as many as 40 protected areas (NatureServe 2018).