Caulophyllum thalictroides

As treated here (following Kartesz 1994, FNA 1997, vol. 3, and Weakley and the Southeastern Flora Team 2024), excludes Caulophyllum giganteum. Kartesz (1994) does not recognize infraspecific taxa within C. thalictroides. Some authors consider this species to have a variety giganteum, with a broadly similar but somewhat more restricted range. FNA (1997, vol. 3), Kartesz (1999), and Weakley and the Southeastern Flora Team (2024) treat this as a separate species, Caulophyllum giganteum. This plant is quite similar, differing primarily only in size (FNA 1997, vol. 3), and could be easily confused and cross-collected with C. thalictroides.

This species is has a very broad range and is frequently encountered in a wide variety of wooded habitats across its range. Nevertheless, it is uncertain how collection pressure will fluctuate over the coming years, and as with most herbs of medicinal value future changes in the market may put increased pressure on this species (Suggs pers. comm., Blakley pers. comm.). An amount estimated between 10,000 and 25,000 lbs. (dry) was traded last year, all of which came from wildcrafting sources since there are no significant cultivation sources for this species in the medicinal market (Blakley pers. comm.). A larger market is predicted in the near future for this species (Suggs pers. comm., Blakley pers. comm.), and efforts to cultivate this species are just beginning. Such cultivation efforts may require large investments before they become economically viable. The information on abundance and trends in population status indicates concern but its uncertainty also indicates the need for better information and monitoring.

Eastern North America, from New Brunswick and Nova Scotia and southernmost Quebec (Labrecque pers. comm.) west to southeastern Manitoba (Punter pers. comm.) and eastern South Dakota (Ode pers. comm.); south to Oklahoma, Arkansas (USDA-NRCS 1999), northern Alabama (Schotz pers. comm.); east to the mountains of the Carolinas (Schafale pers. comm., Pittman pers. comm.). Primarily in the ridge and valley and Blue Ridge sections of the mid-Atlantic states (Frye pers. comm., Schafale pers. comm., Pittman pers. comm.), not found in piedmont or coastal plain.

Several hundred to thousands of populations exist rangewide. Iowa: dozens to hundreds; Kansas: 3; Maryland: hundreds; North Carolina: >1000 (Kauffman pers. comm.); Nebraska: 3 to 20; Rhode Island: 2; South Carolina: 12; South Dakota: 16; Tennessee: 43+; Vermont: thousands; Manitoba: 7 to 15; Quebec: >100 (Brumback and Mehrhoff 1996, APSU 1999).

Extensive in the southern Appalachian Mountain region, perhaps over 1000 populations in North Carolina mountains alone (Kauffman pers. comm.). Not all documented populations range-wide may be extant, which really would require updated surveys throughout the species' range (Punter pers. comm.).

Since this is such a common species throughout much of its range, these numbers can only be estimates. Additional information on species distribution and the number of populations can be gleaned from county occurrence dot maps (USDA-NRCS 1999).

Small and Catling (1999) indicate that this species is harvested in the wild in North America, and in certain areas is considered at risk from collection pressures (Punter pers. comm.). Some predict an increased market for this species in the near future (Suggs pers. comm.).

There is evidence, obtained from a reliable source, of plant collecting from wild populations for the plant trade in central Tennessee; national forests in North Carolina; and in Hoosier National Forest, Indiana.

Plants have been collected from national forest lands for medicinal plant trade from 3 Ranger Districts in the North Carolina mountains; all of the collection permits were obtained within the last 4 years (Kauffman pers. comm.). Illegal collection is likely to be at or in excess of the amount specified below for the legal permits (Kauffman pers. comm.). Most of the collection of this species in the North Carolina mountains is occurring in the Black and Craggy Mountain ranges (Kauffman pers. comm.). A few permits were requested from Hoosier National Forest prior to the cessation of herb collection permitting there recently (Jacquart pers. comm.). This species is traded overseas, though currently the U.S. market for this species is relatively small (Blakley pers. comm.). Apparently, this species is being actively sought on the Chinese and Korean black market, where it gets prices between $15-30 per pound (dry weight; Corbin pers. comm.). Wildcrafters and tradesmen are very quiet and proprietary about how much is collected and where (Suggs pers. comm., Penskar pers. comm., Corbin pers. comm.), so information on amounts is very difficult to come by. In Tennessee, this plant is collected from the wild and sold as nursery stock (Warren Co. Nursery). Most or all material on the market is from wildcrafted sources (Blakley pers. comm., Fletcher pers. comm.). There are reports that migrant workers are now being employed for wildcrafting, which has resulted in much more thorough collection from populations of other species (Corbin pers. comm.).

Forest Service collection permits: 1996: 10 lbs. (dry); 1997: 200 lbs. (dry); 1998: 100 lbs. (dry); 1999: 600 lbs. (dry) (Kauffman pers. comm.).

An amount estimated between 10,000 and 25,000 lbs. (dry) was traded last year, all of which came from wildcrafting sources since there are no significant cultivation sources for this species in the medicinal market (Blakley pers. comm.). A large dealer in herbs based in the southern Appalachians sold 8,000-10,000 lbs. (dry) in 1999 (Fletcher pers. comm.).

A person knowledgable about the herbal medicinal trade says that the plant receives moderate to heavy use of perhaps 7000 pounds/year, and that the market is fairly static (McGuffin pers. comm.).

As with all native forest herbs, habitat conversion and development are significant direct threats (Homoya pers. comm., Punter pers. comm., Kunsman pers. comm., Pearson pers. comm., Labrecque pers. comm., Frye pers. comm.). Equally significant threats include habitat fragmentation and displacement by exotic species (Homoya pers. comm., Penskar pers. comm., Frye pers. comm., Steinauer pers. comm., Enser pers. comm.). The alteration of hydrology by development of bluffs above populations may also present a locally significant threat (Penskar pers. comm.). This species and its habitat are vulnerable to grazing and trampling by free-range cattle in portions of its range (Steinauer pers. comm., Ode pers. comm.).