True Unicorn (Aletris farinosa) is a slow growing perennial that inhabits a large area of eastern North America. It grows in disturbed environments, and requires open areas promoted by frequent fires. Though total population is not well understood and subpopulations are declining in some regions, the overall population appears to be stable. The species has been used for medicinal purposes for centuries, but current levels of trade likely have relatively light impact on the population. Though land conversion coupled with a long generation time present the potential for population declines, current evidence does not suggest these threats present a substantial threat to species survival. Due to the large population spread across a large area and the absence of major threats, the species is listed as Least Concern.

True Unicorn (Aletris farinosa) grows in eastern North America from New England south to eastern Texas and central Florida. The northwest extent of the range includes Wisconsin, Michigan, and areas of Ontario southwest of Toronto at an elevation between 0 and 2,000 metres (Flora of North America Association 2008). Throughout this range it has a patchy distribution and is absent from large areas. It is locally rare in many regions, particularly within the northernmost extent of its range and has likely been extirpated from Maine and New Hampshire (NatureServe 2018).

Population estimates are unavailable outside of areas where True Unicorn is locally rare. In Ontario, remnant subpopulations were estimated in 2014 to number around 14,600 plants (COSEWIC 2015). A 1998 assessment of remnant populations in Rhode Island suggests 41,000 plants are present at a single 2,300 m² location (Killingbeck et al. 1998). Given the wide range of the species and the prevalence of high density stands, it is likely that the population is very large. Despite rarity in some regions, the population is apparently stable and does not appear to be declining (NatureServe 2018).

Ture Unicorn is a perennial herb that grows to one metre in height. It is tolerant of a variety of habitats ranging from bogs to dry prairies and upland wooded areas (Flora of North America Editorial Committee 2002) but requires coarse, slightly acidic soils (COSEWIC 2015). It generally benefits from disturbance, flourishes in areas where fire has removed tree cover, and readily colonizes bare sand (Killingbeck et al. 1998). True Unicorn is a slow growing plant that may have a generation length between seven and fifteen years (COSEWIC 2015).

Threats to True Unicorn include conversion of native prairie habitat for farmland and urban development (COSEWIC 2015) as well as silviculture (NatureServe 2018). Suppression of natural fire regimes also contributes to degradation of existing habitat (COSEWIC 2015). Harvest of wild plants for medicinal trade may have an impact on population as well as the number of subpopulations, but the magnitude of this impact is not well established. Trade appears to be focused on the homeopathic market and trade for phytopharmaceutical uses is minimal.

Native American usage of the plant includes treatment of gastrointestinal issues by the Catawba, and Micmac as well as usage for a diverse group of symptoms by the Cherokee (Moerman 2018). Early European colonizers described use of the plant along the Atlantic coast for the treatment of pain and dysentery (Austin 2004). The dried root of True Unicorn was a component of preparations marketed to 19^th century American women for treatment of delayed menstruation, prolapsed uterus, and inflammation of the uterus (Lans et al. 2018). Sales of plant as an herbal remedy continue today despite the toxicity of the root. Usage has expanded to include high-end moisturizers (Brucculieri 2018) and homeopathic remedies for human and veterinary application (Rajkumar et al. 2006). Current levels of collection of wild specimens for the medicinal trade are variable but averaged 413 kg of dried root per year between 2000 and 2010 (American Herbal Products Association 2012). This data is based on surveys and likely underestimates the total volume of trade. Some root cultivation occurs, but it is estimated to be around 15% of total production (NatureServe 2018). At the time of writing, online root buyers are advertising prices around $80-90 per kg of dried roots.

The species is listed as Threatened in Ontario under the provincial Endangered Species Act 2007 and Threatened on Schedule 1 of the Federal Species at Risk Act (SARA) (Environment Canada 2015). It is noted to be rare in several US states and has likely been extirpated from Maine and New Hampshire (NatureServe 2018). It is listed as Threatened in New York, Endangered in Pennsylvania, and Special Concern in Rhode Island (NRCS 2018). Outside of areas where it is specifically protected, the species is incidentally included in a number of protected areas (IUCN and UNEP-WCMC 2018). United Plant Savers lists the species as At-Risk indicating that the species should be sourced from cultivated populations whenever possible (United Plant Savers 2022).