Goldenseal (Hydrastis canadensis) : COSEWIC assessment and status report 2019

Official title: COSEWIC Assessment and Status Report on the Goldenseal (Hydrastis canadensis) in Canada 2019

Committee on the status of Endangered Wildlife in Canada (COSEWIC)
Special concern 2019

COSEWIC assessment summary

Assessment summary – May 2019

Common name: Goldenseal

Scientific name: Hydrastis canadensis

Status: Special concern

Reason for designation: Increased survey effort has resulted in the discovery of new subpopulations of this species since the last assessment. Although the number of mature individuals of this long-lived plant appears to be stable in recent decades, the remaining subpopulations remain subject to threats from deforestation, harvesting, and invasive species.

Occurrence: Ontario

Status history: Designated threatened in April 1991. Status re-examined and confirmed in May 2000. Status re-examined and designated special concern in May 2019.

COSEWIC executive summary

Goldenseal
Hydrastis canadensis

Wildlife species description and significance

Goldenseal is a herbaceous perennial that grows to 10 to 50 cm tall. It is characterized by its gnarled yellow rhizome (underground stem), which bears scars (left from annual stems) that look like the wax seals historically used to close letters (hence the name “Goldenseal”). The plant bears one to three leaves, each with five lobes. Plants were used as a traditional herbal medicine by Indigenous peoples in North America. Goldenseal is still a species of commercial interest and is an ingredient in various herbal products.

Distribution

Goldenseal occurs from southern Vermont and southern Ontario to southern Wisconsin and south to Arkansas and northern Georgia. It was historically abundant in the central portion of its range. In Canada, the species occurs only in southwestern Ontario, representing 1.6% of its natural range.

Habitat

Goldenseal occurs in deciduous woodlands that experience periodic flooding (that is, floodplains). Patches of Goldenseal are generally found on slightly acidic soils under closed to semi-open canopies (that is, in slightly disturbed sites, such as adjacent to walking paths, sloughs and drainage ways, in woodlot edges, previously flooded areas, thickets, successional forests, on riverbanks, or at the edges of ditches). The species appears to prefer mesic sites where the topography is level with mounds and depressions, or gradually sloping.

Biology

Goldenseal reproduces both by seed and vegetative spread, yet seedlings are rare in Canada. A single white flower is produced in May. During maturation (July to August), several young berries fuse into a single, red, globose aggregate fruit containing 10 to 30 seeds. New shoots develop from the underground stem after the fruit matures. Goldenseal is pollinated by generalist pollinators and dispersed by animals, including birds.

Population size and trends

Twenty-five Goldenseal subpopulations are considered extant in Ontario. This number includes 10 subpopulations that existed in 1998 and were reported in the previous status report, and six newly recorded subpopulations. The other nine subpopulations had been on record but not part of the 1998 survey. An additional five subpopulations are considered to be historical. These have not been relocated as a result of imprecise locational information. An additional subpopulation has been deemed extirpated.

Goldenseal is a clonal plant that forms dense patches within a site. Stems were counted to estimate population size. An estimated 200,015 stems (42,045 mature, flowering) in 207 separate patches were counted at 15 subpopulations in 2015. Given the dense, clonal growth of this species, the stem count is an underestimate, particularly for very large patches of plants that could not be directly counted due to limited survey time.

The Goldenseal population in Ontario is considered currently stable, albeit likely at smaller occurrence levels than at pre-settlement times, with some patches increasing and others decreasing depending on site conditions.

Threats and limiting factors

This species has declined in past decades due to habitat loss and harvesting. Current threats include clearcut logging, invasive species, recreational activities, and water management (for example, drainage ditches). The potential threat of harvesting of Goldenseal remains, yet there is no evidence that extant subpopulations are currently subject to harvesting. In terms of limiting factors, Goldenseal does not spread by seed within the majority of subpopulations and is potentially limited by the absence of natural disturbance and dispersal agents.

Protection, status, and ranks

Goldenseal was assessed by COSEWIC as Threatened in May 2000 and is listed as Threatened on Schedule 1 of the federal Species at Risk Act (SARA); in May 2019, COSEWIC reassessed the species as Special Concern. Goldenseal is also listed as threatened under Schedule 4 of the Ontario Endangered Species Act 2007. The species is also included in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The Convention regulates international trade in underground parts (that is, roots, rhizomes) as well as whole plants. CITES export permits are required for whole plants as well as underground parts in whole, parts, or powdered. Finished products are not regulated (for example, extracts or capsules). It is listed in the IUCN Red List as Vulnerable.

Technical summary

Scientific name: Hydrastis canadensis

English name: Goldenseal

French name: Hydraste du Canada

Range of occurrence in Canada: Ontario

Demographic information

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines(2011) is being used)

Approximated at 40 years
Stem scars observed in 1998 and 2015 would indicate that some flowering plants are at least 37 years old and plants may be substantially older. (See the Biology section)

Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?

No (observed, inferred or projected).

Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]

Not applicable

[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations]

Unknown. Substantial but unknown reduction in mature stems inferred over the last 120 years (3 generations) from historical forest loss. More recently, four subpopulations have declined, and five have increased, leading to an overall observed 29.6% increase in mature stems since the last assessment in 2000, which is unlikely to be sufficient to offset historical losses. (See section Population sizes and trends – Fluctuations and trends)

[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations]

Unknown. Counts at a subset of subpopulations suggest localized recent increases of 7.4% per year (annual growth rate for mature stems is 1.074). This rate of increase cannot be extrapolated to 3 generations, however. (See section Population sizes and trends – Fluctuations and trends)

[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future

Unknown. Increase in population size observed over the past 20 years may continue in the future.

Are the causes of the decline a) clearly reversible and b) understood and c) ceased?

a. No
b. Yes
c. No, not completely. Historical levels of clearcutting have ceased but some subpopulations still potentially face threats from deforestation, harvesting, and invasion by non-native species.

Are there extreme fluctuations in number of mature individuals?

No

Extent and occupancy information

Estimated extent of occurrence (EOO)

28 821 km²

Index of area of occupancy (IAO) (Always report 2x2 grid value)

144 km²

Is the population “severely fragmented” that is, is >50% of its total area of occupancy in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?

a. No
b. No

Number of “locations”^* (use plausible range to reflect uncertainty if appropriate)

25

Is there an [observed, inferred, or projected] decline in extent of occurrence?

Yes. No evidence of recent decline, although historical levels of habitat conversion lead to inferred reductions in extent of occurrence.

Is there an [observed, inferred, or projected] decline in index of area of occupancy?

Yes. No evidence of recent decline, although historical conversion of habitat results in inferred reductions in area of occupancy.

Is there an [observed, inferred, or projected] decline in number of subpopulations?

No recent declines in the number of subpopulations but historical declines are inferred.

Is there an [observed, inferred, or projected] decline in number of “locations”*?

No recent declines in the number of locations but historical declines are inferred.

Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?

An inferred historical decline in area and extent of forest habitat.

Are there extreme fluctuations in number of subpopulations?

No

Are there extreme fluctuations in number of “locations”?

No

Are there extreme fluctuations in extent of occurrence?

No

Are there extreme fluctuations in index of area of occupancy?

No

^* See definitions and abbreviations on COSEWIC website and International Union for Conservation of Nature (IUCN) (Feb 2014) for more information on this term.

^a Editorial note: This table has been modified to remove precise location information (EO#). Please contact the COSEWIC Secretariat if you require this information.

Quantitative analysis

Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years]: Quantitative analysis not available.

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Was a threats calculator completed for this species? Yes. Date: March 20, 2017. Participants: Dwayne Lepitzki, Jana Vamosi, Adrianne Sinclair, Holly Bickerton, Daniel Brunton, Susan Meades, Bruce Bennett, Ruben Boles and Karolyne Pickett.

1. Biological resource use - 5.3 Logging and wood harvesting (medium-low impact)
2. Biological resource use - 5.2 Gathering terrestrial plants (low impact)
3. Human intrusions and disturbance – 6.1 Recreational activities (low impact)
4. Natural system modifications – 7.2 Dams and water management/use (unknown impact) and 8.1 Invasive non-native species (unknown impact)

Rescue effect (immigration from outside Canada)

Status of outside population(s)?

Michigan (S2), New York (S2), Ohio (S4S5), Pennsylvania (S4)

Is immigration known or possible?

Immigration is not known.
Immigration is considered very unlikely.

Would immigrants be adapted to survive in Canada?

Unknown, but likely. No genetic studies have been conducted within Canada to ascertain local adaptation.

Is there sufficient habitat for immigrants in Canada?

Yes

Are conditions deteriorating in Canada?⁺

Yes, minimally. Habitat appears largely stable but invasive species have been detected near several subpopulations.

Are conditions for the source population deteriorating?⁺

No

Is the Canadian population considered to be a sink?⁺

No

Is rescue from outside populations likely?

Unlikely

⁺ See Table 3 (Guidelines for modifying status assessment based on rescue effect).

Data sensitive species

Is this a data sensitive species? Yes. It is of commercial interest. Because this species can be harvested and sold as a medicinal plant, a written request to COSEWIC (with assurances to safeguard site information) is required to obtain locational data.

Status history

COSEWIC: Designated threatened in April 1991. Status re-examined and confirmed in May 2000. Status re-examined and designated special concern in May 2019.

Status and reasons for designation

Status: Special concern

Alpha-numeric codes: Not applicable

Reasons for designation: Increased survey effort has resulted in the discovery of new subpopulations of this species since the last assessment. Although the number of mature individuals of this long-lived plant appears to be stable in recent decades, the remaining subpopulations remain subject to threats from deforestation, harvesting, and invasive species.

Applicability of criteria

Criterion A (Decline in total number of mature individuals): Not met. Population is currently stable.

Criterion B (Small distribution range and decline or fluctuation): Not met. EOO currently exceeds threshold. Although the distribution of this species has likely been reduced within the past three generations and the IAO is below the threshold for Endangered, there are >5 locations, no recent overall decline observed, and no evidence of fluctuations.

Criterion C (Small and declining number of mature individuals): Not met. The number of mature individuals exceeds thresholds.

Criterion D (Very small or restricted population): Not met. The number of mature individuals and the IAO exceeds thresholds. No threats are known to be severe enough to drive the species to become critically endangered in a short period of time.

Criterion E (Quantitative analysis): Not done.

Preface

This status assessment includes data from fifteen subpopulations not included in the previous assessment (2000). Nine of these subpopulations were already on record in 2000, but the inclusion of the other six subpopulations is considered most likely the result of increased inventory work rather than actual population expansion. Survey work also documented additional patches within known subpopulations.

Five subpopulations had been considered as “historical” in COSEWIC’s previous assessment. No attempt was made to relocate these subpopulations during surveys undertaken in 2015.

COSEWIC history

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions (2019)

Wildlife species

A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.

Extinct (X)

A wildlife species that no longer exists.

Extirpated (XT)

A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.

Endangered (E)

A wildlife species facing imminent extirpation or extinction.

Threatened (T)

A wildlife species likely to become endangered if limiting factors are not reversed.

Special concern (SC)
(Note: Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.)

A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.

Not at risk (NAR)
(Note: Formerly described as “Not In Any Category”, or “No Designation Required.”)

A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.

Data deficient (DD)
(Note: Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” [insufficient scientific information on which to base a designation] prior to 1994. Definition of the [DD] category revised in 2006.)

A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.

The Canadian Wildlife Service, Environment and Climate Change Canada, provides full administrative and financial support to the COSEWIC Secretariat.

Wildlife species description and significance

Name and classification

Scientific name: Hydrastis canadensis L.

Common name: Goldenseal, Ground Raspberry, Indian Dye; Hydraste du Canada, Sceau d’or

Family: Ranunculaceae, buttercup family

Major plant group: Dicot flowering plant

Morphological description

Goldenseal is a perennial herb with a gnarled rhizome (underground stem) that bears conspicuous scars from the yearly loss of the single, aboveground stem (Figure 1). The stem is hairy and attains a height of 10 to 50 cm. It bears one basal and two cauline leaves that are palmately lobed, with 5 to 7 broad, obovate lobes that have serrate margins. A flower stalk borne at the top of the stem produces a single greenish-white flower with showy stamens but no petals (Figure 1). The fruit is an aggregate of 1 to 2-seeded dark red berries (Figure 2).

Population spatial structure and variability

The Goldenseal population in Ontario is currently comprised of 25 subpopulations. There are another five historical subpopulations that could not be relocated due to imprecise locality information, and one other subpopulation considered extirpated (NHIC 2017).

For Goldenseal, the COSEWIC term “subpopulation” (COSEWIC 2015) corresponds reasonably well to the habitat-based plant element occurrence delimitation standards (NatureServe 2004) where a subpopulation is defined as a group of occurrences that are separated by less than 1 km; or if separated by 1 to 3 km, with no break in suitable habitat between them exceeding 1 km; or if separated by 3 to 10 km but connected by linear water flow and having no break in suitable habitat between them exceeding 3 km. The term “site” was used in the previous status report in a similar fashion but was defined as separated by other sites by at least 0.5 km, similar to the NatureServe definition of “occurrence”. To remain consistent with the previous report, we have continued with the use of the term “site”, where more than one site can be nested within a single subpopulation (see Table 1).

Each site can consist of a single dense patch or several patches within wooded habitat as well as scattered individual stems. Patches are defined as distinct groups of densely distributed aboveground stems that are within at least 5 m from another group.

Totals in 1998:
Patches: 74
Stems: 16030
F/B: 4390
L: 11640

Totals in 2015:
Patches: 207
Stems: 200015
F/B: 42045
L: 159900

^b SP = subpopulations defined using NatureServe (2004) standards whereby occurrences are lumped into a single subpopulation if separated by less than 1 km, or if separated by 1 to 3 km with no break in suitable habitat between them exceeding 1 km, or if separated by 3 to 10 km but connected by linear water flow and having no break in suitable habitat between them exceeding 3 km.
^c Sites defined as at least 0.5 km apart; numbers included allowing comparison with previous status report.
^d Patches defined as dense clusters of plants separated from any other dense cluster by at least 5 m.
^e F/B = mature two-leaved stem with flower or berry.
^f L = single-leaved non-flowering stem.
^g Data are from previous surveys (Sinclair, personal communication)
^h Data are from a 2010 survey.
ⁱ Data are from a 2005 survey. It has been surveyed since 2005 but the stems were estimated using different methodology which does not allow for comparison.
^j Data for site 28 are from a 2016 record.

Goldenseal is pollinated by generalist pollinators (small polylectic bees, syrphid flies, and some larger bees, see Biology) and dispersed by animals including birds (see Dispersal and migration). While pollinator and disperser range may limit gene flow between subpopulations in forest fragments, there have been no genetic analyses of Canadian subpopulations to test this hypothesis. Subpopulations in the United States have received a limited amount of study (Oliver and Leaman 2018); Inoue et al. (2013) performed an analysis of RAPD markers in 11 wild populations sampled from North Carolina, Ohio, Pennsylvania, and West Virginia and found that ~81% of the genetic variation occurs within subpopulations. Zhou and Sauvé (2006) applied AFLP analysis to determine the genetic relationships between nine Goldenseal accessions from the southern states (Tennessee, Georgia), finding high levels of genetic divergence between regions. At a smaller geographical scale, Torgerson (2012) measured the genetic variation in six Goldenseal sites in western North Carolina using an allozyme analysis and found low genetic diversity both within and between populations. Overall, it is difficult to extend these findings to the Canadian population, and there is equivocal evidence on the level of genetic diversity and divergence between geographically separated sites.

Designatable units

In Canada, Goldenseal occurs only in a small part of southwestern Ontario in the Great Lakes Plains Ecological Area (COSEWIC 2007). There is currently no evidence of morphological or genetic differentiation that would warrant more than a single designatable unit.

Special significance

Goldenseal is a species with documented medicinal properties (Small and Catling 1999). It was used by indigenous peoples and is still used in a variety of commercial herbal products (for example, tinctures, throat spray, pills). Cultivated sources largely supply international markets currently (Table 2).

Distribution

Global range

Goldenseal occurs from southern Vermont and southern Ontario to southern Wisconsin and south to Arkansas and northern Georgia (Figure 3). It was historically most abundant in the central portion of its range in the states of Indiana, Kentucky, Ohio, and West Virginia. The estimated global range is 1,250,000 km² (NatureServe 2015).

Canadian range

In Canada, Goldenseal is restricted to a small area of southwestern Ontario in the Mixedwood Plains Ecozone (Crins et al. 2009, Figure 4). The range in Canada represents a small part (1.6%) of the global range.

Figure 4. Historical, extirpated, and extant subpopulations of Goldenseal in Ontario, Canada. *Editorial note: This map has been removed to remove precise location information. Please contact the COSEWIC Secretariat if you require this information.

Figure 5. Individually numbered extant subpopulations of Goldenseal in Ontario, Canada (see Table 2). *Editorial note: This map has been removed to remove precise location information. Please contact the COSEWIC Secretariat if you require this information.

The Canadian distribution is based on specimens or photographs in various herbaria (White 1991), and on records from the Natural Heritage Information Centre database (NHIC 2017). Thirty-one subpopulations in total are known. The current status of each subpopulation is classed as extant if mature individuals were observed during the past 20 years (since 1998) and not known to be recently extirpated; historical if recent search effort is lacking or very limited but the species has been observed within the past 40 years (since 1978) but, is presumed extant if suitable habitat likely persists and extirpated if failed to find on last thorough search and the habitat is likely no longer suitable. Sites were presumed extirpated if the last observation was more than 40 years ago (prior to 1978), regardless of search effort. These definitions are consistent with the NatureServe species occurrence ranking approach (Hammerson et al. 2008).

According to these definitions, twenty-five subpopulations of Goldenseal are considered extant (Table 1). Of the remaining six, five subpopulations are historical and have not been re-located recently (recorded in 1889, 1942, 1958, 1975, probably 1980, Figure 4). These historical subpopulations have insufficient geographical information but the vague locality information provided situates the subpopulations within areas that still have suitable habitat. Therefore, according to the year they were last observed, four of these historical subpopulations can be viewed as presumed extirpated, while one is presumed extant. The final historical subpopulation is considered extirpated (recorded in 1896, last observed pre-1943, considered extirpated in 2010, NHIC 2017).

Extent of occurrence and area of occupancy

The estimated extent of occurrence (EOO) is 28,821 km², measured by drawing the smallest polygon in which no internal angle exceeds 180 degrees and which contains all sites in Ontario. The index of area of occupancy (IAO) is 144 km². The IAO was measured as the surface area of grid cells that intersect the actual area occupied by the wildlife species (that is, the biological area of occupancy). This IAO was calculated based on a grid with a cell size of 2 km x 2 km.

The previous status report (COSEWIC 2000) reports 21 extant sites in 1998. One of these sites, which would be considered a subpopulation according the NatureServe (2004) definition, dates back to an herbarium record in 1976 with the note “persisting and escaped from cultivation”. It is outside the natural distribution range and was noted in the 1991 status report as “naturalized from earlier cultivation” (White 1991). Human intervention at the site was not apparent in more recent years (site visited in 1998, 2000). It was not visited in 2015. The site is outside the natural range, the source of the subpopulation is unknown, and it was not established for conservation purposes. The subpopulation is therefore considered an extra-limital introduction and is excluded from this assessment (COSEWIC 2010). All known cultivated sites are also excluded from the assessment (COSEWIC 2010).

Search effort

Early reports of Goldenseal came from untargeted botanical surveys. The earliest report of Goldenseal in Canada is an herbarium record collected near Wingham, Ontario by James A. Morton in 1889 (University of Western Ontario (UWO)).

In 1989, White investigated “a number of sites” and other field botanists confirmed additional sites for a total of 16 sites verified since 1960 (White 1991). It is difficult to accurately determine the number of subpopulations represented by these 16 sites according to the definition of subpopulation used in this report (NatureServe 2004), but upon review of the information provided in the 2000 report (COSEWIC 2000), it is estimated at 10 subpopulations.

In 1998, Sinclair carried out a targeted survey of known sites, collating the reported records in the previous status report (White 1991), herbarium records, and from discussion with local field biologists. Sinclair, with a field assistant, surveyed 11 subpopulations from May 8 to June 6 1998 and searched 11 sites for potential subpopulations (approximately four to nine hours at each site). Sites were walked in linear parallel transects, about 10 m apart. When a patch was located, searches were done in a series of circles outwards. The information was submitted to NHIC (survey results are reported in Sinclair and Catling 2000b, COSEWIC 2000, and NHIC 2017) and formed the basis for the 2000 status report (COSEWIC 2000), with the addition of new records.

Further untargeted search effort generated six subpopulations (SP 12, 14, 15, 16, 17, 24) after the 1998 survey (conservation authority records; NHIC 2017, Table 1). While these subpopulations were likely to have been extant at the time of the 1998 survey, they were first recorded in later years (2005, 2007, 2009, 2010) during surveys by various agencies on their properties (for example, conservation authorities, Ontario Parks, etc., carried out Ecological Land Classification (ELC) work including documentation of species at risk). These subpopulations are close to where Goldenseal was already known to occur (for example, in woodlands further up the river; Sinclair’s field observations from 1998 and 2015 surveys as well as various site visits in 1999, 2000, 2001, and 2005).

During an Ecological Land Classification mapping project (ELC; 2008 to 2010), two Goldenseal subpopulations were surveyed. This process involved two people surveying two subpopulations over an estimated 470 hours (67 days). One conservation authority spent several full days in 2005 surveying and estimating number of stems at the one Goldenseal subpopulation on their property (over 140,000 stems in over 85 patches). Ontario Ministry of Natural Resources and Forestry have also spent time carrying out species at risk surveys, including subpopulations where Goldenseal was known to occur.

In 2015, Sinclair, Bickerton and staff members from conservation authorities and Ontario Parks spent 93 hours searching and surveying 12 subpopulations (120 patches of plants) over 11 days (Bickerton and Sinclair 2016). No attempt was made to relocate the five subpopulations considered historical, that is, the three areas reported as ‘not found in 1998’ and one of the two areas reported as ‘could not be surveyed in 1998’ in the previous status report, plus one area that should have been included as ‘not found in 1998’ in the previous status report (Editorial note: This text has been modified to remove precise location information, EO#. Please contact the COSEWIC Secretariat if you require this information.) (Lamb, personal communication 1998). One additional subpopulation first observed in 1896 and last observed before 1943 is considered extirpated as of 2010 according to the Natural Heritage Information Centre of Ontario (Editorial note: This text has been modified to remove precise location information, EO#. Please contact the COSEWIC Secretariat if you require this information).

Habitat

Habitat requirements

Goldenseal is restricted to bottomland deciduous woodland in floodplains (that is, riparian areas) as well as uplands occasionally flooded in the spring.

Goldenseal patches on upland sites occur on medium acidic (pH 5.4 to 6.3) sandy loam or loam soils in fairly mature mesic woods under closed canopies. Dominant trees include Red Oak (Quercus rubra), Sugar Maple (Acer saccharum), and hawthorn (Crataegus spp.), with ash (Fraxinus spp.) and Shagbark Hickory (Carya ovata). It is usually found where topography is level with mounds and depressions.

Goldenseal in floodplains occurs on medium acidic to slightly alkaline (pH 5.7 to 7.8) clay or sandy loam soils in fairly mature dry mesic to mesic woods near rivers under closed to semi-open canopies (with canopy cover levels of 50 to 70%). Dominant trees include Shagbark Hickory, Ironwood (Ostrya virginiana), and Basswood (Tilia americana) with elm (Ulmus spp.) and ash being common. These near-floodplain woods would be periodically flooded during major flooding events. Topography at these sites is flat or gradually sloping to the water edge. Most floodplain sites are semi-open disturbed woodland edges between water and agricultural land where raspberry (Rubus spp.), Northern Spicebush (Lindera benzoin), and introduced woody shrubs are common. Goldenseal can often be found in areas with some level of disturbance such as: adjacent to or within walking paths, sloughs and drainage ways, at woodlot edges, in previously flooded areas, thickets, in successional forests, on riverbanks, and on the edges of ditches (Sinclair and Catling 2000b).

In 2010 and 2015, Goldenseal was recorded within 11 different vegetation communities (ELC communities, Appendix 1), suggesting that Goldenseal has relatively generalized habitat requirements within deciduous woodlands in Ontario.

Habitat trends

Goldenseal is restricted to bottomland deciduous woodland near floodplains as well as upland habitat that is rarely flooded in the spring. Only remnants of these woodland communities remain (see Canadian range). Extreme southwestern Ontario forests have been reduced to less than five percent of what existed in pre-settlement times (Pearce 1997), with estimates that this has reduced forest cover from 80% to 11% in Carolinian Canada (Carolinian Canada Coalition 2018).

Remaining woodland occurs as fragments within an agricultural and urban landscape. How forest cover losses translate to loss of habit for Goldenseal depends on the distribution of Goldenseal within these forest remnants. In Ohio, ~50% of historical occurrences were considered extirpated (Mulligan and Gorchov 2004) due to a combination of deforestation, vegetation change through deer browsing, and overharvesting. In Canada however, four historical subpopulations can still be considered possibly extant because suitable habitat likely exists in these areas (although they have not been located for at least 40 years). Only one of the historical subpopulations has been deemed extirpated (in 2010, NHIC 2017).

While the habitat of Goldenseal has been historically greatly restricted, the habitat for the remaining subpopulations is considered currently largely stable. In 2015, ash dieback was observed by Sinclair and Bickerton in some woodlots presumably because of the Emerald Ash Borer (Agrilus planipennis); however, ash was not a dominant tree (see Habitat requirements). The habitat has generally remained unchanged between 1998 and 2015.

Biology

Life cycle and reproduction

Goldenseal reproduces by seed and vegetative propagation (clonal growth) from the underground rhizome. Goldenseal has a yellow knotty rhizome with numerous roots along its length. In late summer or early fall, a new bud is produced on the rhizome from which a new stem, or ramet, grows during the following year. Growth begins early the next year and stems usually achieve full size by mid-May. Stems can also be produced from latent buds on the rhizome (Sinclair pers. obs. 1999 to 2001). In early May (in Ontario, Canada), aboveground Goldenseal stems produce a flower (Figure 1). In July and August, the aggregate fruit ripens and contains up to 30 seeds (Figure 2).

Goldenseal exhibits a mixed-mating breeding system and flowers can set seed autogamously (that is, without pollinators; Sanders 2004). Generalist pollinators have been observed visiting the flowers (small polylectic bees, syrphid flies, and some larger bees; Sinclair et al. 2000) where pollen is likely transferred between flowers growing from the same rhizome (self-pollination). Seeds remain dormant in the soil for approximately 10 months before germinating the following spring (Sinclair pers. obs.). After fruits mature, root growth occurs and buds begin to develop from the rhizome (Eichenberger and Parker 1976).

Based on comparisons between the 1998 and 1989 field surveys and the 2015 and 1998 field surveys, Goldenseal reproduces in Ontario primarily by clonal growth. Seedlings were rarely observed (none or only a few seen during stem counts). Samples (1 m² quadrats) of 14 sites were also monitored from 1998 to 2000. A 15% increase in stem number occurred between 1998 and 2000, mostly involving small stems — seedlings were not observed (Sinclair and Catling 2002).

This clonal plant is considered to have a long generation time. Goldenseal reaches reproductive maturity from seed within 5 to 7 years (Oliver 2017), yet existing plants in the Canadian population appear to be at least 20 years old (and perhaps as old as 100 years, given that the rhizome decays over time and depending on how long the woodlot has been in existence). A rough estimate of the age of plants in Canadian subpopulation was gained from data collected on flowering plants surveyed in 1998, which were in large, dense (and presumably old) clones, with the few excavated rhizomes revealing 10 to 20+ stem scars. Considering that these same plants were surveyed in 2015, it can be ascertained that rhizomes can live at least 27 to 37+ years, and many are likely to be older (rhizomes can fragment over time such that a single mature individual, or genet, can be difficult to sample). Based on this information, generation time is estimated to be approximately 40 years.

Physiology and adaptability

Goldenseal is a robust perennial species. Subpopulations are able to expand through vegetative propagation over time. Goldenseal also appears to prefer and benefit from certain kinds of disturbance (Sinclair and Catling 2000a, 2000b, 2003, 2004). The species can be found in canopy gaps and, like many other Carolinian species, is probably adapted to spread in situations with higher light penetration. However, recent studies indicate that mortality is higher in canopy gaps (Johnson 2017).

Goldenseal can be easily transplanted using rhizomes. It can be propagated from rhizome pieces, seed, buds, and/or one-year-old seedlings under natural or artificial shade. It is most easily and reliably propagated by rhizome pieces (Sinclair and Catling 2001). Transplants established in Ontario subpopulations in 1999 (Sinclair and Catling 2003, 2004) have persisted without intervention (Sinclair pers. obs. 2015).

Based on field observations (Sinclair pers. obs.), and recommendations from growers’ experience, Goldenseal is susceptible to drought and other ecological negative implications of complete removal of the forest canopy. It cannot survive without some level of shade (yellowed and browned, dried-out leaves that appear burnt have been observed in full exposure to sunlight). Seeds do not appear to tolerate dry conditions (for example, only 134 of 4000 seeds germinated during a large field experiment in 1999 during a dry season; Sinclair 2002).

Like many other species in the Ranunculaceae family, Goldenseal produces a number of secondary metabolites, such as hydrastine and berberidine, which are alkaloids likely providing protection from herbivores (Mithöfer and Boland 2012) or pathogenic fungal endophytes (Tims 2006). The subpopulations in Canada were not observed to show signs of damage from insect attack or vertebrate grazing (see Threats). The bioactive alkaloids in Goldenseal are of interest in the herbal medicine industry, particularly for fighting inflammation and infection (for example, Ettefagh et al. 2010). As a consequence of having these properties, the species has been susceptible to harvesting in the past and harvesting is still considered a serious threat outside Canada (Mulligan and Gorchov 2004), yet there is no evidence that wild harvesting is currently affecting subpopulations in Canada.

Dispersal and migration

Goldenseal spreads clonally within patches. Seedling recruitment is rarely observed in Ontario (A. Sinclair, pers. obs. 1998 to 2015). The fruit is displayed at the top of the stem and reported to be eaten by birds and mammals, although observations are limited (for example, Sinclair et al. 2000). In general, fruit were removed within days of ripening and rarely seen on the ground during Ontario field studies (Sinclair, pers. obs. 1999 to 2001). Few fruit removal events have been directly observed, but Sinclair et al. (2000) did witness fruit removed by a Red-winged Blackbird (Agelaius phoeniceus), confirming previous accounts that birds play a role in seed dispersal (Tait 2006).

Interspecific interactions

Generalist insect pollinators are likely important for transferring pollen between flowers. One study observed patches of Goldenseal over a period of two days and observed visits from the following genera: Hoverflies (Eupiodes spp.), Mining bees (Andrena spp.), Sweat bees (Augochlora spp., Dialictus spp., Evylaeus spp.), Bumblebees (Bombus spp.) (Sinclair et al. 2000). Birds and mammals are reportedly required (see Dispersal and migration above) to disperse seeds within the woodland habitat in order for the plant to spread.

Goldenseal does not appear to be directly impacted by deer grazing and it out-competes other plants in its patches. Evidence of disease was not observed in Ontario subpopulations (Sinclair, pers. obs. 1998 to 2015). However, disappearance of historical occurrences of Goldenseal was associated with areas that experience heavy deer browsing in Ohio (Mulligan and Gorchov 2004).

Population sizes and trends

Sampling effort and methods

Population size during the 2015 survey was determined by extrapolating data from directly counting stems. Methods used to estimate population size were consistent with those used in 1998 (Sinclair 2002). Two-leaved and single-leaf stems were directly counted in all patches that were <10 m². Two (or more)-leaved stems are considered mature stems (because they produce fruit) and represent the estimates of mature individuals (see Tables 1 and 3). In large patches of Goldenseal (>10 m²), subpopulation size was estimated by multiplying the average number of counted stems in two randomly placed 1 m² quadrats (one in the middle where stems are most dense and one within the edge where stems are relatively less dense) by total estimated patch area (surveyor’s tape measure used). The estimates are considered underestimates of stems given the density of the patches (approximately one stem for every 5 stems could be missed in dense patches and possibly one stem for every 25 in less dense patches (Sinclair pers. obs.). Further, not enough time was available to comprehensively survey one site with thousands of stems (Site 1B). Based on the ratios of flowering to non-flowering stems found at other sites, stems with fruit were counted at this site and multiplied by a factor of 2.5 to estimate the number of non-flowering stems.

As explained under Search effort above, 12 subpopulations where permission was granted were surveyed (plants searched for and stems counted) in 2015 by Sinclair, Bickerton, and six members of their team over 11 days.

Abundance

There are an estimated 197,968 Goldenseal stems (41,533 mature) in 207 separate patches in Ontario in 15 subpopulations (Table 1). This number is an underestimate of stems given the dense clonal growth of the plant particularly for very large patches of plants (>10 m²) that could not be directly counted due to limited survey time.

Several subpopulations (Table 1) were not resurveyed recently, but are considered extant (NHIC 2017). The site surveys from 1998 yielded a total estimate of 2047 stems (512 mature) in 25 patches. Combining this with the more recent estimates (from the paragraph above) yields a total estimated population size of 200,015 stems (42,045 mature) in 232 patches in 17 subpopulations. Population abundance data are lacking for the eight other subpopulations.

Fluctuations and trends

Additional survey effort since 1998 resulted in the addition of six newly recorded subpopulations (SP 12, 14, 15, 16, 17, 24), verification of previously recorded subpopulations, as well as more patches per subpopulation (Table 1). It is reasonable to consider that the same number of subpopulations existed in 1998 as documented in this report. The recently discovered subpopulations are thus most likely a result of increased search effort rather than newly established subpopulations. Herbarium records indicate that Goldenseal was already known to occur in the surrounding areas where the subpopulations were discovered.

With 16 subpopulations reported in 1960 (White 1991) and 25 subpopulations in 2015, the number of subpopulations appears relatively stable to slightly increasing over the last 55 years. However, historical data are lacking to assess how this level of occupancy compares to the Goldenseal population 120 years ago.

All patches of plants recorded in 1998 except one were relocated within revisited subpopulations. Many more patches were recorded in 2015 at several subpopulations (Table 3). Patches known but not found in 1998 had been found by 2015. The number of patches has increased between years likely due to increased survey effort.

^k F/B = mature two-leaved stem with flower or berry
^l L = single-leaved non-flowering stem

Seedlings were rarely observed in Ontario(none or only a few seen during stem counts (Sinclair and Catling 2002), but were not quantified in the survey efforts in 2015). Seedling establishment appears to be lower in Ontario than in other parts of Goldenseal’s range (Christensen and Gorchov 2010). Seed dispersal and seedling establishment are unlikely to be a large contributing factor in the increase in number of patches observed in Canada between 1998 and 2015, given the large dense patches that were observed and newly recorded in 2015 (large, dense patches are indicative of older, established genets). However, the cause of the large increase in the number of patches in some subpopulations is currently unknown. Despite using the same methods and same observer, the survey data still represents an estimate and error could be significant.

For subpopulations that were surveyed in both 1998 and 2015 (Table 3), an overall increase of 35.2% (all stems) and 29.6% (mature stems) was recorded. Based on these two surveys, some patches increased substantially in size and others decreased substantially (that is, the increases observed overall are driven by increases in only five sites; Table 4).

Goldenseal population growth in Canada has been modelled using previous survey data (Sinclair et al. 2005). The average population growth rate estimated from that study was 1.062 ± 0.053, which did not significantly differ from the equilibrium value (1.0) suggesting that the Canadian population of Goldenseal is stable to slightly increasing. However, growth rates among subpopulations varied largely and had wide confidence intervals (due to both large inter-individual differences in stem mortality, growth, and fertility and small sample sizes of the Goldenseal subpopulations).

Using the recent stem counts (Table 3), the annual growth rate calculated from 1998 to 2015 was 1.059 for non-flowering stems, 1.074 for flowering stems, and 1.063 for all stems, as computed with:

${\displaystyle \text{λ}={\left(\frac{{\text{<mn><em>N</em></mn>}}_{}}{{\text{<mn><em>N</em></mn>}}_{}}\right)}^{\mathrm{1/17}}}$

Based on modelling and repeated field surveys, Goldenseal in Ontario can be characterized as having an overall stable to slightly increasing growth rate. Caution must be applied to this projection as it is based on comparison between counts in two years taken 17 years apart. The counts in the previous status report (COSEWIC 2000) could not be used because the methods used to estimate stem counts were not consistent. In the previous status report, counts were from 1998 with counts of additional stems and patches added to the 1998 numbers based on site visits in 1999, 2000, and 2001.

Rescue effect

It is unlikely that dispersal beyond Goldenseal’s Canadian range could occur. Immigration is unlikely given the distance between Canada’s subpopulations and those in the United States. Even if fruits/seeds could be transported across that distance, the chance of seeds reaching suitable germination sites is low.

Threats and limiting factors

Threats

Direct threats to extant subpopulations were assessed for each species using the IUCN (International Union for Conservation of Nature) unified threats classification system (Master et al. 2012). Threats are defined as the proximate activities or processes that directly and negatively affect the population. Results on the impact, scope, severity, and timing of threats are presented in Appendix 2.

Goldenseal subpopulations in Canada face potential threats (see Threats calculator in Appendix 2) from logging, harvesting and recreational activities, resulting in an overall threat impact level of medium-low. A number of threats have been identified with unknown impact as well (Appendix 2). These are discussed below, listed under their corresponding IUCN threats classification scheme headings (IUCN 2016).

Logging and wood harvesting (5.3 medium-low impact)

Clearcutting poses the most severe threat to this species. The adoption of Good Forestry Practices under Ontario’s Forestry Act has diminished the amount of legal clearcutting in woodlots in southern Ontario, yet the legality of clearcutting can vary depending on woodlot land tenure, jurisdictional authority, and harvest details. Selective logging could also occur at sites where this species is found; however, Goldenseal would likely be less impacted from selective logging. Goldenseal was once thought to thrive in canopy gaps yet recent studies have shown higher mortality in gaps (Johnson 2017).

Gathering terrestrial plants (5.2 low impact)

Gathering terrestrial plants is considered a conceivable threat due to the medicinal value attributed to the species. In the case of Goldenseal in Ontario, evidence of gathering plants was not observed between 1998 and 2015, but illegal harvesting may depend on ill-conceived and poorly understood demand. Of note, there are reports that Goldenseal can mask the use of illicit drugs and allow a user to pass a urine test, despite there being no scientific evidence for the efficacy of this practice (Schwarcz 2017). At the very least, three subpopulations are in close proximity to recreational trails on public lands and could be subject to this threat.

Recreational activities (6.1 low impact)

All-terrain vehicle (ATV) trails were noted at three subpopulations (~4% of the Canadian population) and these were the same trails noted in 1998. No trails were observed running through patches of plants. Goldenseal has been observed growing in ATV trails (Sinclair fieldwork from 1998 to 2001) but it has been noted that one patch at one subpopulation was extirpated due to a widening of an ATV trail. ATVs cause soil disturbance, which may have benefited Goldenseal in terms of seedling recruitment in the past.

Dams and water management/use (7.2 unknown impact)

There is potential for water management at three upland subpopulations (~1% of the Canadian population). Drainage ditches could dry out the soil where individuals are found, which is not ideal for this species (evidence of dry withered plants in one subpopulation after drainage ditches created in the early 2000s) because it prefers more moist conditions. The plants seem to be able to recover if dry conditions are only temporary (plants at the subpopulation were thriving in 2015 and the patches greatly expanded), although less moisture could also affect seedling establishment.

Invasive non-native/alien species/diseases (8.1 unknown impact)

European Common Reed (Phragmites australis subsp. australis) has been observed spreading recently in two of the drainage ditches discussed above. Although this invasive species does not appear to be currently impacting Goldenseal, its presence in the vicinity represents a potential threat. Garlic Mustard is present at three subpopulations but the effect on Goldenseal is currently unknown. The presence of other invasive and non-native species (for example, Common Buckthorn (Rhamnus cathartica) and Glossy-leaved Buckthorn (Rhamnus frangula) have been noted as present at four other sites, which could potentially be impacting Goldenseal, but there is no evidence of direct impact on Goldenseal currently.

Limiting factors

The Canadian population of Goldenseal is not limited by fruit (and seed) production but it does not appear to spread readily throughout its habitat by seed, even though seeds are viable. Sexual reproduction has been observed to contribute to population growth in more southern regions of the global range of Goldenseal (Christensen and Gorchov 2010). In Ohio, near the centre of the historical range of Goldenseal, 12.5% of new recruits were seedlings (Christensen and Gorchov 2010).

In Canada, establishment of new patches appears to be a rare event. Possible factors include limited dispersal by animals, poor seed germination, or low rates of seedling survival but more study is required to quantify the contributions to poor seedling recruitment. Spread of Goldenseal may be limited by lack of certain kinds of disturbance that occurred naturally in the past, such as flooding of bottomland forests, fires that burned mesic deciduous woodlands, and effects of colonial birds and large mammals such as fertilization and soil disturbance (Sinclair and Catling 2000a, 2003, 2004). Such natural disturbance may have promoted spread through dispersal of seeds and rhizome pieces as well as improved conditions for seedling establishment.

Number of locations

Goldenseal subpopulations in Canada are currently facing potential threats from logging and harvesting (see Threats). Because the likelihood of logging and harvesting at any site can vary depending on woodlot land tenure and jurisdictional authority, any single event affecting all individuals in multiple subpopulations simultaneously is unlikely. Thus, all extant subpopulations are considered as single locations (IUCN 2017).

Protection status and ranks

Legal protection and status

Goldenseal was assessed by COSEWIC as Threatened in May 2000 and it is listed as Threatened on Schedule 1 of the federal Species at Risk Act (SARA); in May 2019, COSEWIC reassessed the species as Special Concern. Goldenseal is also a species listed as Threatened under Schedule 4 of the Ontario Endangered Species Act 2007. The plant is included in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). CITES regulates international trade in underground parts (for example, roots and rhizomes) as well as whole plants. CITES export permits are required for whole plants and underground parts in whole, parts, or powdered. Canada does not issue CITES export permits for wild specimens (Environment and Climate Change Canada, 2017). Finished products are not regulated (for example, extracts or capsules).

The Ontario Ministry of Natural Resources and Forestry has published a recovery strategy for Goldenseal (Jolly 2016). Environment and Climate Change Canada has posted a proposed recovery strategy for Goldenseal under the federal Species at Risk Act (consultation period ended on May 27, 2018; Environment and Climate Change Canada 2018).

Non-legal status and ranks

Globally, Goldenseal is considered to be G3G4 (vulnerable to apparently secure, last assessed 2012; NatureServe 2015; Oliver personal communication 2016). It is ranked N2 (imperilled, 18 October 2012; NatureServe 2015) in Canada and N3N4 (vulnerable to apparently secure, last assessed 2012) in the United States. In 2012, NatureServe did a comprehensive literature review in order to update the G-rank and US N-rank and ran the species through the Red List Assessment. Goldenseal has been assessed as vulnerable (Oliver 2017). Some states have not updated ranks since the review (Oliver personal communication 2016).

At the provincial level, Goldenseal is ranked S2 (imperilled) in Ontario. In the United States, it is ranked critically imperilled (S1) in Connecticut, Kansas, Massachusetts, Minnesota, Mississippi, New Jersey, and Vermont; imperilled (S2) in Alabama, Georgia, Maryland, Michigan and New York; vulnerable (S3) in Delaware, Indiana, Iowa, North Carolina, and Virginia; vulnerable to apparently secure (S3S4) in West Virginia and Wisconsin; apparently secure (S4) in Illinois, Kentucky, Pennsylvania, and Tennessee; apparently secure to secure (S4S5) in Arkansas and Ohio; and secure (S5) in Missouri.

Habitat protection and ownership

The majority of Goldenseal occurrences are afforded some measure of protection. Eleven subpopulations occur partly or entirely on conservation authority lands (SP1, 2, 8, 11, 14, 15, 19, 20, 21, 22, 23), three subpopulations occur on provincial park lands (SP9, 12, and 13), one subpopulation occurs in a nature reserve (17), and four subpopulations (SP5, 6, 18, and 25) occur on First Nation land where the First Nation is committed to preserving and restoring the natural heritage (Table 1). The other six subpopulations are on private land. These subpopulations on private land could be threatened by habitat alteration where building a cabin or a long-term road through a woodlot could eradicate a patch.

Acknowledgements and authorities contacted

The report writer was able to do the fieldwork and write the report as an employee of the Canadian Wildlife Service thanks to Carolina Caceres, Manager of COSEWIC and CITES Science, and Basile van Havre, Director of Population and Conservation Management. With the support of the Species at Risk Stewardship Fund of the Ontario Ministry of Natural Resources and Forestry, Holly Bickerton did the 2015 field survey with the report writer and compiled all data. James Page of the Canadian Wildlife Federation created maps of the survey data. The fantastic staff of the Ausable Bayfield Conservation Authority (ABCA), Ian Jean, Deb Brown, Nicole Luney, Gabriela Skibinski, and Denise Iszczuk, helped carry out surveys on their properties, including locating patches in advance and surveying subpopulations on their own. Ian Jean continued to provide support by answering a multitude of questions about the ABCA properties and previous survey work. Melody Cairns, Pilar Manorome, Jennifer Chambers, and summer students with Ontario Parks helped survey plants in 2015 and clarify information from past survey work. Shane White of the St. Clair Region Conservation authority also surveyed plants in 2015. Dan Lebedyk of the Essex Region Conservation Authority provided reports from past surveys and many helpful insights. Charles Cecile also expedited the field survey by being a helpful guide. The report writer thanks all landowners who gave permission to survey. This incredible combined effort truly enhanced the knowledge of the species given only one week could be allocated to the field survey. What a week! Bruce Bennett, SSC Co-Chair of the Vascular Plants Species Specialist Subcommittee, Mike Oldham of the Ontario Natural Heritage Information Centre, and Karen Timm of the COSEWIC Secretariat graciously provided advice during write up of the draft report. Lorna Brownlee of the CITES Scientific Authority analysed the CITES trade data. Alain Filion and Jenny Wu of the COSEWIC Secretariat kindly carried out mapping and associated calculations for the report. Finally, Patrick Nantel helped verify growth rate calculations. This report is the result of an unbelievable network of high quality people who were so willing to help and give their time in the interest of Goldenseal conservation.

Authorities contacted

COSEWIC Secretariat, Environment and Climate Change Canada, Gatineau, QC

Furrer, Martina, Biodiversity Information Biologist, Ontario Natural Heritage Information Centre, Ontario Ministry of Natural Resources and Forestry, Peterborough, ON

Jacobs, Clint, Walpole Island Heritage Centre, Walpole Island First Nation, Ontario

Jean, Ian, Forestry and Stewardship Specialist, Ausable Bayfield Conservation Authority, Exeter, ON

Lebedyk, Dan, Conservation Biologist, Essex Region Conservation Authority, Essex, Ontario

Oldham, Mike, Botanist, Ontario Natural Heritage Information Centre, Ontario Ministry of Natural Resources and Forestry, Peterborough, ON

Ontario Region, Canadian Wildlife Service, Environment and Climate Change Canada, Downsview, ON

White, Shane, Maintenance Foreman, St. Clair Conservation Authority

Zammit, Tony, Aquatic and Terrestrial Ecologist, Grand River Conservation Authority Cambridge, ON

Original status report writer (1990): David J. White

Updated report writers (2000): Adrianne Sinclair and Paul M. Catling

Information sources

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Biographical summary of report writer

Dr. Adrianne Sinclair wrote her PhD thesis at the University of Ottawa on the recovery of Goldenseal based on fieldwork over four years. Her research began with the 1998 field survey to relocate and attempt to find additional Goldenseal sites. The results of the survey were provided to COSEWIC and the Ontario Natural Heritage Information Centre and used to write the update status report published in 2000. Shortly after completion of her PhD thesis in 2002, Adrianne took a contract with the Canadian Wildlife Service to evaluate the impact of international trade on Goldenseal. Adrianne is currently the Head of the Scientific Authority for the Convention on International Trade in Endangered Species (CITES) at the Canadian Wildlife Service.

Collections examined

No collections were examined specifically for this report but the report uses locality data compiled from the following collections for the 1998 survey: CAN, DAO, TRT, HAM, WAT, UWO, and QK (acronyms from Thiers 2016).

Appendix 1. Goldenseal vegetation communities

In 2015 (12 subpopulations) and 2010 (1 subpopulation not visited in 2015), Goldenseal was recorded within the following 11 different vegetation communities (ELC communities):

• FODM2-2 Dry - Fresh Oak - Hickory Deciduous Forest
• FODM5, Fresh-Moist Sugar Maple Deciduous Forest Ecosite
• FODM5-1, Dry-Fresh Sugar Maple Deciduous Forest
• FODM5-2, Fresh-Moist Sugar Maple - Beech Deciduous Forest
• FOD5-8, Dry-Fresh Sugar Maple-White Ash Deciduous Forest Type
• FODM6-1, Fresh-Moist Sugar Maple-Lowland Ash Deciduous Forest
• FODM6-2, Fresh-Moist Sugar Maple - Black Maple Deciduous Forest
• FODM7-5, Fresh-Moist Black Walnut Lowland Forest
• FODM9-1, Fresh-Moist Oak - Sugar Maple Deciduous Forest
• FODM9-4, Fresh-Moist Shagbark Hickory Deciduous Forest
• FODM9-5, Fresh-Moist Bitternut Hickory Deciduous Forest
• WODM5, Fresh-Moist Deciduous Woodland Ecosite (dominated by Black Walnut)
• WODM5-2, Fresh-Moist Elm Deciduous Woodland

Appendix 2. Threat calculator for Goldenseal

Threats assessment worksheet

Species or ecosystem scientific name:

Goldenseal (Hydrastis canadensis)

Element ID:

Not applicable

Elcode:

Not applicable

Date:

20/03/2017

Assessor(s):

Dwayne Lepitzki (facilitator), Jana Vamosi (Vascular Plants SSC Co-chair), Adrianne Sinclair (report writer), Holly Bickerton (report contributor), Daniel Brunton, Susan Meades, Bruce Bennett (Vascular Plants SSC members), Ruben Boles and Karolyne Pickett (CWS), Joanna James (COSEWIC Secretariat)

References:

Bickerton and Sinclair 2016

Assigned overall threat impact:

CD = Medium - Low

Impact adjustment reasons:

Overall impact assigned as Medium-Low. This once widespread Canadian population seems to be stable and possibly increasing in remnant patches, and ~half of the population is located in protected areas. Potential threats exist but are not currently impacting the population.

Overall threat comments:

Generation time = 40 years, therefore the timing for this threats calculator is 100 years (maximum). Subpopulation #16 is a potentially introduced population but is considered part of the Canadian population since it falls within the natural range for this species.

Classification of threats adopted from IUCN-CMP, Salafsky et al. (2008).