COSEWIC Assessment and status report on the Spotted Wintergreen (Chimaphila maculata) in Canada, 2017

Spotted Wintergreen

Spotted Wintergreen
Photo: © Jenny McCune, with permission.


COSEWIC Assessment and status report on the Spotted Wintergreen (Chimaphila maculata) in Canada, 2017

COSEWIC Assessment and status report on the Spotted Wintergreen

COSEWIC
Committee on the Status
of Endangered Wildlife
in Canada

COSEWIC logo

COSEPAC
Comité sur la situation
des espèces en péril
au Canada

COSEWIC status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows:

COSEWIC. 2017. COSEWIC assessment and status report on the Spotted Wintergreen Chimaphila maculata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xii + 39 pp. (Species at Risk Public Registry website).

Previous report(s):

COSEWIC. 2000. COSEWIC assessment and update status report on the spotted wintergreen Chimaphila maculata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 6 pp.

White, D.J. 1998. Update COSEWIC status report on spotted wintergreen Chimaphila maculata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 1-6 pp.

Kirk, D.A. 1987. COSEWIC status report on the spotted wintergreen Chimaphila maculata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 36 pp.

COSEWIC would like to acknowledge Holly Bickerton and Melinda Thompson for writing the status report on the Spotted Wintergreen, Chimaphila maculata, in Canada, prepared under contract with Environment and Climate Change Canada. This report was overseen and edited by Del Meidinger, Co-chair of the COSEWIC Vascular Plants Specialist Subcommittee.

COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment Canada
Ottawa, ON
K1A 0H3

Tel.: 819-938-4125
Fax: 819-938-3984
E-mail: COSEWIC E-mail
Website: COSEWIC

Également disponible en français sous le titre Évaluation et Rapport de situation du COSEPAC sur la Chimaphile maculée (Chimaphila maculata) au Canada.

Spotted Wintergreen in flower. Photo by Jenny McCune, with permission.



Spotted Wintergreen
Chimaphila maculata

Spotted Wintergreen (Chimaphila maculata) is a small, low-growing, evergreen perennial that is woody at the base and spreads by rhizomes to form colonies. Each stem consists of a whorl of thick, blue-green, toothed leaves with a white stripe along the mid-rib and white areas extending from the mid-rib. Topping the whorl of leaves is a stalk supporting one to five nodding white or pinkish flowers. In a given year, only some of the stems in a subpopulation produce flowers. The rounded seed capsules become erect after flowering, and contain numerous tiny seeds.

Spotted Wintergreen occurs in eastern North America, Mexico, and Central America. Its range in eastern North America extends from southern Michigan and Ontario, east to southern New Hampshire and Maine, and south to Mississippi and northern Florida. Historically, Spotted Wintergreen was more widely distributed in southern Ontario and into southwestern Quebec. It is now restricted to a few subpopulations in southern Ontario and is considered extirpated in Quebec.

Spotted Wintergreen is a woodland understorey species typically associated with dry–fresh oak and oak–pine mixed forests and woodlands. The plant tends to occur on well-drained sandy soils free of coarse fragments, with low organic content and poor nutrient status.

Spotted Wintergreen flowers in late July to early August. It can reproduce either clonally or by seed. As stems arise from creeping rhizomes, clumps or contiguous groupings of stems likely represent ramets rather than unique genetic individuals. The tiny, dust-like seeds in this family are dispersed mainly by wind.

In Canada, there are currently five extant subpopulations. Surveys between 2011 and 2014 show a total Canadian population of at least 3587 (~3600) stems. The number of genetic individuals is not known, although it is presumably smaller. Previously reported population sizes are in the vicinity of a few hundred stems; however, two of the extant subpopulations (and several smaller sites) have been discovered since the most recent status report, and both are significantly disjunct from other extant sites. These probably do not represent newly established subpopulations, but may reflect increased survey effort and reporting of observations. Most sites known since around 2000 have remained at least stable, while some have increased in abundance and extent, evidenced by regular monitoring.

There are additionally two historical and six extirpated subpopulations. There is a possibility that plants persist at either historical site. Most of the extirpated records are only known through vague locality or population information and have never been relocated. One small subpopulation discovered near Montréal in 1992 may have been planted and is now believed to be extirpated.

Recreational activities are probably the predominant threat to extant subpopulations of Spotted Wintergreen; however, fire has the potential to have the greatest impact as this species appears to not persist after fire. Most extant sites are in public ownership and are protected from loss due to development but many sites are publicly accessible, and a few may be vulnerable to ATV damage and soil compaction from adjacent walking trails. Many sites do not appear to have any imminent threats, although their small size and spatial extent make them vulnerable to even localized disturbances. Invasive species are present at or near a few sites, but do not appear to negatively affect ramet (or shoot) numbers within these subpopulations. Habitat degradation (e.g., by garbage dumping) may also have limited impacts on some Spotted Wintergreen subpopulations. This species may be limited to some degree by its dependence on soil mycorrhizae and its reproductive biology.

Spotted Wintergreen was first assessed as Endangered by COSEWIC in 1987. This status was re-examined and confirmed in 1998 and 2000. The species is currently listed as Endangered under the Species at Risk Act and under Ontario’s Endangered Species Act (ESA).The species and its habitat in Ontario are protected under the ESA. The global conservation status rank for Spotted Wintergreen is G5, secure. In Canada, Spotted Wintergreen is ranked N2 (imperilled). In Ontario, it is ranked S2 and in Quebec is it ranked SX. Spotted Wintergreen is considered secure (N5) in the United States, but within the U.S., it is considered critically imperilled (S1) in Illinois, and imperilled (S2) in Vermont, Maine, and Mississippi. The species is also legally protected in Illinois, where it has been designated as Endangered.


Demographic information
Summary items 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).

The minimum age to germination and flowering estimated to be at least 2-3 years. However, the ability of the species to reproduce vegetatively suggests the average age of mature individuals is probably at least 10 years, and possibly much older.

Unknown, but likely at least 10 years, and possibly longer

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

Comparisons of all subpopulations over two time points suggest that since 2000, the number of mature individuals (approximated by stem count) is certainly stable and is probably increasing. Two new subpopulations (and several sites within others) have been discovered in the last decade, although this probably reflects increased survey effort. Since the last status report (~15 years or 1.5 generations), one subpopulation has been extirpated and two others are now historical, although these represent very few mature individuals within the total population.

No
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations] Unknown

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

Two new subpopulations have been documented, but these may not represent new sites. Several previously known and monitored sites show significant increases in the number of stems and in occupied area since 2000. Within the last 10 years, two subpopulations are now considered historical but may still exist, and one has probably been lost.

Population stable to increasing

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

If surveys and planned habitat management are continued at Turkey Point and St. Williams Forest, the total number of stems may continue to increase.

Possibly increasing
[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
Are the causes of the decline a.clearly reversible and b.understood and c. ceased? N/A
Are there extreme fluctuations in number of mature individuals? No
Extent and occupancy information
Summary items Information
Estimated extent of occurrence (EOO) – current 1952 km2
Index of area of occupancy (IAO) (Always report 2 x 2 grid value). 28 km2
Is the population “severely fragmented” i.e., 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? Unknown
Number of “locations”
See Definitions and Abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term. (use plausible range to reflect uncertainty if appropriate) Five extant subpopulations; multiple threats but fire is likely the most significant threat to most of the population and is likely to be variable in intensity and area of impact, hence a range of plausible locations.
7-9

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

Significant decline due to loss of some locations. See report for a discussion of methods of calculating both past and current EOO values.

Yes

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

See report for a discussion of methods of calculating both past and current IAO values.

Yes, 22% decline observed since 2000.

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

Two subpopulations are considered “historical”, but may still exist. The Quebec subpopulation is not included since it is considered to have been introduced.

Yes
Is there an [observed, inferred, or projected] continuing decline in number of “locations”
See Definitions and Abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term.?
Yes
Is there an [observed, inferred, or projected] continuing decline in [area, extent and/or quality] of habitat? Unknown
Are there extreme fluctuations in number of subpopulations? No
Are there extreme fluctuations in number of “locations”
See Definitions and Abbreviations on COSEWIC website and IUCN (Feb 2014) for more information on this term.?
No
Are there extreme fluctuations in extent of occurrence? No
Are there extreme fluctuations in index of area of occupancy? No
Number of mature individuals (in each subpopulation)
Summary items Information
Subpopulation 1 – St. Williams Forest (2012) 2065 stemsa
Subpopulation 2 – Turkey Point Area (2012) 928 stems
Subpopulation 3 – Fishers Glen Area (2012, 2013) 579 stems
Subpopulation 4 – Perry Road, Wainfleet (2012) 5 stems
Subpopulation 5 – Ojibway Park, Windsor (2014) 10 stems
Total ~3600 stems b

a Stem counts are an index of population abundance. The number of mature individuals is not known, but is presumably lower than stem counts for this clonal plant. For St. Williams Forest subpopulation, 2065 represents a minimum estimate, because new patches have been found following habitat restoration in 2014, 2015, and 2016. Revised counts are not yet available but it is likely that this number has increased (Heagy pers. comm. 2016).

b Rounded to reflect uncertainty in estimates of larger patches.

Quantitative analysis
Summary items Information
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years] Not done
Threats (direct, from highest impact to least, as per iucn threats calculator)
Summary items Information

Was a threats calculator completed for this species?

In March 2016. See Appendix 1.

Participants: Del Meidinger (co-chair), Kristiina Ovaska (Facilitator), Holly Bickerton (writer), Karen Timm and Joanna James (Secretariat), Sean Blaney, Andy MacKinnon, Joyce Gould, Melinda Thompson, Audrey Heagy, Mike Oldham, Jenny McCune Recreational activities and habitat degradation present the most likely threats to Canadian subpopulations; however, fire has the potential for the greatest impact. Other minor threats include the possibility of development on private lands, as well as fire suppression. Invasive species are present at low levels within habitat, but their impact is unknown.
Rescue effect (immigration from outside Canada)
Summary items Information

Status of outside population(s) most likely to provide immigrants to Canada?

In the adjacent northern states of Maine and Vermont, populations appear to be increasing, with recent new reports; however, Spotted Wintergreen may also have been under-reported in the past (Cameron pers. comm. 2015; Popp pers. comm. 2015).

Spotted Wintergreen is a common plant in dry oak and pine woodlands in southern New England and is particularly abundant along the Atlantic Coastal Plain in southern New England (see Atlas of the Flora of New England, Angelo and Boufford 2016).

Stable, and possibly increasing
Is immigration known or possible? Possible, but low probability overall
Would immigrants be adapted to survive in Canada? Probably
Is there sufficient habitat for immigrants in Canada? Yes

Are conditions deteriorating in Canada?

The two largest sites are publicly owned and are undergoing habitat restoration leading to observed population increases. Three additional subpopulations have been recently discovered or rediscovered. The Fisher’s Glen and Perry Road (Wainfleet) sites are thought to be of poor viability with habitat possibly deteriorating.

Overall no, but some local declines
Are conditions for the source population deteriorating? Stable and possibly increasing
Is the Canadian population considered to be a sink? No

Is rescue from outside populations likely?

Recolonization from populations outside Canada is possible, as Spotted Wintergreen is present in adjacent Michigan and New York, and dust seeds may travel long distances. Establishment may be limited by the presence of compatible soil mycorrhizae.

Possible
Data sensitive species
Summary items Information
Is this a data sensitive species? No
Status
Summary items Information
COSEWIC: Designated Endangered in April 1987. Status re-examined and confirmed Endangered in April 1998 and in May 2000. Status re-examined and designated Threatened in April 2017.
Status and reasons for designation
Summary items Information
Recommended Status Threatened
Alpha-numeric code B1ab(i,ii,iv)+2ab(i,ii,iv)
Reasons for designation This small, low-growing perennial plant is restricted to sandy soils in southern Ontario. Since the last assessment, this species has been found at two new sites and lost at two others. The overall population has remained fairly stable but the five subpopulations are under threat from recreational activities and the possibility of wildfire.
Applicability of criteria
Summary items Information
Criterion A (Decline in Total Number of Mature Individuals) Not met. The number of mature individuals (approximated by stem count) is stable.
Criterion B (Small Distribution Range and Decline or Fluctuation) Meets Threatened B1ab(i,ii,iv)+2ab(i,ii,iv); EOO (1952 km2) and IAO (28 km2) meet the threshold for Endangered but the number of plausible locations (7-9) meets the Threshold for Threatened. Declines observed in EOO, IAO and in number of locations/subpopulations due to loss of small historical occurrences. Continuing loss is possible due to recreational activities and possibility of fire. The population is not severely fragmented and does not undergo extreme fluctuations.
Criterion C (Small and Declining Number of Mature Individuals) Not met. The small population (3600 stems) meets Threatened threshold but cannot infer future declines of 10% based on recent population data so C1 does not apply. Subpopulation sizes and number of mature plants do not meet threshold for C2--one subpopulation exists with over 1000 mature plants; and no single subpopulation comprises all of population. There is not an extreme fluctuation in mature individuals.
Criterion D (Very Small or Restricted Population) Not met.
Criterion E (Quantitative Analysis) Not done.

Spotted Wintergreen (Chimaphila maculata) was assessed as Endangered in 1987 because it was known from very few localities in Canada (Kirk 1987). The main threats to Spotted Wintergreen were thought to be trampling and recreational pressure (COSEWIC 2000). Since the most recent COSEWIC assessment of Spotted Wintergreen in 2000, several sites have been rediscovered and two new subpopulations have been located. Surveys from 2011-2014 suggest that the abundance of Spotted Wintergreen, indicated by stem counts, is certainly stable, and may be increasing. Overall population size and trends are somewhat difficult to determine due to differences in survey effort and counting methods in the last two decades.

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.

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 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.

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


Scientific Name: Chimaphila maculata (L.) Pursh

Synonyms: Chimaphila maculata (L.) Pursh var. maculata, Pyrola maculata L.,

Chimaphila maculata var. dasystemma (Torrey ex Rydberg) Kearney & Peebles

English Common Names: Spotted Wintergreen, Mottled Pipsissewa, Striped Wintergreen, Striped Prince’s Pine

French Common Name: Chimaphile maculée

Major Plant Group: Eudicot flowering plant

Family: Ericaceae

Spotted Wintergreen, Chimaphila maculata, is one of five species in the genus Chimaphila, three of which occur in Canada. Common Pipsissewa, Chimaphila umbellata, overlaps in range with Spotted Wintergreen, but the species are distinct and no hybrids have been documented.

Spotted Wintergreen is a small, low, rhizomatous evergreen perennial that is woody at the base (Figure 1). Plants can rarely reach heights of 50 cm (Freeman 2009), but Ontario plants are generally less than 20 cm in height. Each shoot bears several whorls of smooth blue-green lanceolate or ovate-lanceolate sharply toothed leaves from 2.5-7 cm long with prominent white venation including a central white stripe. Individual stems support a terminal cluster of one to five white or pinkish nodding flowers up to 2 cm wide (Kirk 1987; Standley et al. 1988). The fruit is a roundish capsule up to 1 cm across (Freeman 2009). Seeds are small (0.4–0.6 mm long, 0.1–0.2 mm wide), and wingless (Kirk 1987). The seeds of Spotted Wintergreen are believed to be dispersed by wind, and possibly by water (Amador et al. 2013).

Genetic individuals (genets) can spread via rhizomes, so that a patch of stems may represent one or more genetic individuals. Standley et al. (1988) assumed that clumps of stems represented single clones, and found an average clump size of 16 stems (range: 1-90 stems) based on two populations in southern Massachusetts.

Spotted Wintergreen is similar to Common Pipsissewa; the two species appear to have similar habitat requirements and often co-occur where their ranges overlap. They differ in that Common Pipsissewa has very shiny solid green oblanceolate leaves, which lack the diagnostic central white stripe and white veins on the upper surface. DNA barcoding techniques are available to successfully distinguish among the five Chimaphila species globally (Liu et al. 2013).

Figure 1. Chimaphila maculata fruiting.
Fruiting
Photo: © credit: M. Thompson
Long description for Figure 1

Photo of the Spotted Wintergreen, showing stems bearing several whorls of smooth blue-green lanceolate or ovate-lanceolate sharply toothed leaves with prominent white venation, including a central white stripe. At the top of one of the stems are two roundish fruit capsules.

All extant subpopulations are in southwestern Ontario, with most plants occurring in Norfolk County. Two recently discovered subpopulations in Niagara Region and the City of Windsor are disjunct from the remaining extant sites in Norfolk County by 75 and 200 km respectively. Although genetic work has not been completed, it is possible that habitat fragmentation may contribute to restricted gene flow and reduced genetic diversity. However, not enough is known about the population biology of the species to determine the minimum habitat patch size or number of individuals necessary to support a long-term viable population, and it is not known whether the Canadian population is severely fragmented.

A single designatable unit is recognized for Canada. The Canadian population is known only from the Great Lakes Plains National Ecological Area (COSEWIC 2014). There is no evidence or recognition of genetic or morphological differences within this species. Spotted Wintergreen does demonstrate considerable variation morphologically across its North American range, but this does not appear to be correlated to geography (Freeman 2009).

Ethnobotanical studies have reported a number of food and medicinal uses of the genus Chimaphila among many groups of North American Indigenous peoples, as well as early European settlers (Moerman 1998; Pengelly and Bennett 2011).

Spotted Wintergreen is one of five species in the genus Chimaphila worldwide. Members of Chimaphila are partial mycoheterotrophs, meaning that their seedlings require fungal hosts to germinate and develop, and mature plants photosynthesize but can also receive supplementary nutrition via mycorrhizae (Massicotte et al. 2008; Hynson et al. 2009; Johannson and Eriksson 2013).

Spotted Wintergreen is native to eastern North America, Mexico, and Central America. Its range in eastern North America extends from central Michigan and southern Ontario, east to southern New Hampshire and Maine, and south to Mississippi and northern Florida. The western limits appear to be in western Kentucky and Tennessee, and eastern Illinois. Spotted Wintergreen also ranges from Central America, through Mexico to southern Arizona (Figure 2).

Figure 2. North American range of Chimaphila maculata.
North  American Range
Photo: © (after Haber and Keddy 1984; Kartesz 2015)
Long description for Figure 2

Map illustrating the global range of the Spotted Wintergreen. In eastern North America the Spotted Wintergreen extends from central Michigan and southern Ontario, east to southern New Hampshire and Maine, and south to Mississippi and northern Florida. The western limits appear to be in western Kentucky and Tennessee and eastern Illinois. Spotted Wintergreen also ranges from Central America, through Mexico to southern Arizona.

Canadian subpopulations Footnote1 occur in southern Ontario, at the northern edge of the range of Spotted Wintergreen. The total Canadian distribution likely represents less than 1% of the global species’ range. A single disjunct subpopulation was found near Montréal, Quebec and is considered likely to have been introduced. All five extant subpopulations are in Ontario, with almost the entire Canadian population found in Norfolk County (Figure 3).

Historically, Spotted Wintergreenwas likely more widely distributed in southwestern and southcentral Ontario. It is considered extirpated from five sites in the Niagara and Muskoka areas (NHIC 2015; see Table 1). Little is known about these subpopulations, which are known only from old specimens with vague locality information.

A now-extirpated Quebec subpopulation is considered likely to have been introduced. Two stems were observed in Deux-Montagnes in southwestern Quebec in 1992; no plants have been observed since 2000, and the species is considered extirpated (Jacobs 2001). This subpopulation is considered likely to have been introduced because the site has a history of use by the Mohawk people, and Spotted Wintergreen is regarded as an important medicinal plant by many First Nations peoples (Labrecque pers. comm. 2015; Sabourin pers. comm. 2015). The subpopulation is also many hundreds of kilometres distant from other native subpopulations.

Table 1. Subpopulationa counts of Spotted Wintergreen Stems
Population type Site name Ownership Previous record (most, but not all) Year of most recent observation 2011-2014 Abundance (#stems) Comments
Extant subpopulations ST. WILLIAMS FOREST (EO 5501) blank blank blank 2065 stems blank
Extant subpopulations Manester Tract A Provincial Crown Land 1986 – 14 plants (D. Sutherland)
2007 – 25 stems (R. Gould)
2009 – 25 stems (R. Gould)
2012 – not found (M. Thompson)
2009 25 stems Included in total because population probably persists (Gould pers. comm. 2015).
Extant subpopulations Manester Tract B Provincial Crown Land 1988 – 2-3 plants (P. Carson)
2001 – 23 plants (D. Jacobs, M. Thompson)
2002 – 5 stems (R. Gould)
2005 – 36 stems (R. Gould)
2007 – 5 stems (R. Gould)
2009 – 36 stems (R. Gould)
2012 – 23 stems (M. Thompson)
2012 23 stems blank
Extant subpopulations Manester Tract C Provincial Crown Land 1994 – 3 plants (M. Gartshore)
1997 – 3 plants (M. Gartshore)
2000 – 9 plants (1 flowering, M. Thompson, D. Jacobs).
2001 – 8 stems (M. Thompson, D. Jacobs)
2004 – 12 stems (R. Gould)
2007 – 25 stems (R. Gould)
2009 – 25 stems (R. Gould)
2012 – 1 stem (M. Thompson)
2012 1 stem In 2012, unable to find any other plants in the vicinity. Possible that a larger patch was missed, and this represents a solitary stem of a new subpopulation.
Extant subpopulations Nursery Tract Provincial Crown Land 1985 – < 20 plants (M. Gartshore).
1985 – 41 plants (12 flowering, D. Kirk).
1989 – 36 plants (M. Oldham).
1997 – 100 plants (est.) (M. Gartshore)
1997 – 87 plants (15 flowering, D. White)
2000 – 406 plants (~203 flowering, M. Thompson et al.)
2001 – ~500 plants (D. Jacobs, M. Thompson).
2003 – 948 stems (R. Gould)
2005 – 1893 stems (R. Gould).
2012 – ~2000 stems (M. Thompson).
2012 ~2000 stems blank
Extant subpopulations St. Williams Forest (new) Provincial Crown Land 2014 – 16 stems (J. McCune) 2014 16 blank
Extant subpopulations TURKEY POINT AREA (EO 5502) blank blank blank 928 stems blank
Extant subpopulations Turkey Point Tract A Provincial Crown Land 2009 – 7 stems (R. Gould)
2012 – 9 stems (M. Thompson)
2012 9 stems blank
Extant subpopulations Turkey Point Tract B Provincial Crown Land 2004 – 7 stems (R. Gould)
2007 – 8 stems (R. Gould, A. Woodliffe)
2012 – 7 stems (M. Thompson)
2012 7 stems blank
Extant subpopulations Turkey Point Tract C Provincial Crown Land 2004 – 3 stems (R. Gould)
2007 – 13 stems (R. Gould, A. Woodliffe)
2012 – 4 stems (M. Thompson)
2014 – 42 stems (M. Gartshore, J. Chambers)
2012 4 stems blank
Extant subpopulations Turkey Point Tract D Provincial Crown Land 2007 – 2 stems (R. Gould)
2010 – 13 stems (R. Gould)
2010 – 22 stems (D. White)
2010 - Not relocated in 2012, evidence of ATV use. Possibly extirpated.
Extant subpopulations Turkey Point Tract E Provincial Crown Land 2010 – 500 stems (D. White)
2012 – not found (M. Thompson)
2014 – at least 500 stems (M. Gartshore)
2014 500 stems Not relocated in 2012 but in 2014 Mary Gartshore completed a partial count of this "very large" population at 256 stems. Based on conversation with Audrey Heagy, assumed to be stable (possibly increasing) and reported at previous count.
Extant subpopulations Turkey Point Tract F Provincial Crown Land 2012 – 34 stems (R. Gould et al.) 2012 34 stems blank
Extant subpopulations Turkey Point Provincial Park A Provincial Park 2011 – 1 stem (S. Brinker and M. Oldham) 2011 1 stem blank
Extant subpopulations Turkey Point Provincial Park B Provincial Park 2012 – 200 stems (R. Gould) 2012 200 stems blank
Extant subpopulations Turkey Point Provincial Park C Provincial Park 2012 – 6 stems (R. Gould) 2012 6 stems blank
Extant subpopulations Normandale Private (Church Camp) 1996 – 10-15 stems (M. Gartshore)
2000 – 80 plants (D. Jacobs et al.)
2001 – 130 plants (M. Thompson et al.)
2005 – 165 stems (R. Gould)
2012 – 163 stems (M. Thompson)
2012 163 stems blank
Extant subpopulations Normandale – new site Private (Church Camp) 2014 – 4 plants (2 flowering, J. McCune) 2014 4 stems blank
Extant subpopulations FISHERS GLEN AREA (EO 5503) blank blank blank 579 stems blank
Extant subpopulations Fishers Glen Conservation Area Long Point Region Conservation Authority 1921 (T. Ivey)
2000 – 23 plants (D. Leadbeater, K. Ursic)
2001 – 12 plants (M. Thompson)
2002 – 14 stems (unknown)
2003 – 20 stems (unknown)
2005 – 16 stems (unknown)
2006 – 7 stems (R. Gould)
2007 – 51 stems (R. Gould)
2012 – 166 stems (M. Thompson)
2013 – "at least" 529 stems (B. Draper, R. Gould; combined counts)
2013 529 stems blank
Extant subpopulations Spooky Hollow ANSI Hamilton Naturalists' Club 1968 (F.H. Montgomery)
1984 – not found (D. Kirk)
2011 – approx. 50 stems (M. Thompson)
2013 50 stems Surveyors unknown.
Extant subpopulations PERRY ROAD WOODLOT (WAINFLEET) (EO 92678) blank blank blank 5 stems blank
Extant subpopulations Perry Road Woodlot, Wainfleet area, Niagara Region Private 2007 – 7 stems (T. Staton, S. Brinker, M. Oldham)
2012 – 5 stems (M. Thompson)
2012 5 stems On municipal right-of-way, ownership unclear.
Extant subpopulations OJIBWAY PARK (EO 115386) blank blank blank 10 stems blank
Extant subpopulations Ojibway Park City of Windsor 2014 – 10 stems (M. Oldham) 2014 10 stems (M. Oldham) blank
Historical populations Trout Creek (EO 13044) Unknown 1991 – 3 stems (D. Sutherland)
1997 – not found (D. White)
1991 - Possibly overlooked in 1997 (COSEWIC 2000)
Historical populations Wasaga Beach Provincial Park (EO 5506) Provincial Park 1975 – 6 plants (Van Stam and T. Reznicek)
1989 – not found (D. Brunton)
1991 – not found (B. Bowles et al.)
1992 – not found (B. Bowles et al.)
1995 – observed (NHIC database)
1995 – not found (M. Oldham et al.)
2000 – not found (B. Bowles et al.)
2001 – not found (B. Bowles et al.)
1995 - Opinion differs over the likelihood of rediscovering the species at this site.
Extirpated subpopulations Niagara Parks System (EO 92208) Unknown None 1895 blank Observation; Exact location unknown.
Extirpated subpopulations Simcoe (EO 5504) Unknown None 1949 blank Collection; Exact location unknown.
Extirpated subpopulations Fort Erie (EO 5505) Unknown None 1863 blank Collection; Exact location unknown.
Extirpated subpopulations Hamilton (EO 5507) Unknown None 1886 blank Collection; Exact location unknown.
Extirpated subpopulations Baysville, Muskoka District (EO 5511) Unknown None 1904 - Collection; Exact location unknown.
Extirpated subpopulations Parc national d'Oka, Quebec (EO 5702) Provincial Park 1992 – 2 stems (Sabourin et al.)
2000 – 1 stem
2002 – not found
2006 – not found
2000 - Considered likely to have been introduced. Considered extirpated due to absence despite searches. Habitat is present and reasons for disappearance are unknown.

a The term “Subpopulation” as used here following COSEWIC terminology, is equivalent to “Population” in the 2015 federal recovery strategy.

The index of area of occupancy (IAO) and the extent of occurrence (EOO) were not calculated for the previous status report (COSEWIC 2000). Therefore, past and current values have been calculated for this report. All were calculated by the COSEWIC Secretariat based on the best available data provided by provincial Conservation Data Centres--the IAO is based on using a 2 km x 2 km grid.

For the current IAO and EOO, only currently extant subpopulations (2012-2014) were included in calculations (see Table 1).

For the 2000 IAO and EOO, the two now-historical subpopulations (Wasaga Beach and Trout Creek) were included, because they would have been considered extant in 2000, based on NatureServe standards. The Quebec subpopulation was not included since it is presumed to have been introduced. Finally, all subpopulations and observations that have been newly documented since 2000 (e.g., Ojibway Park, Wainfleet) are also included in the 2000 calculations, even though they had not been observed at this time. This assumes that they were extant but undiscovered in 2000. Although it cannot be known whether this is true, it is considered a cautious approach.

Based on these assumptions, the current (2012-2014) IAO for Spotted Wintergreen in Canada is 28 km2. The IAO for Spotted Wintergreen from 2000 is 36 km2. These values indicate a decline of 22%.

The current (2012-2014) extent of occurrence (EOO) is 1,952 km2. The EOO for Spotted Wintergreen from 2000 is 29,340 km2. This represents a 93% decline in area. This large decrease in EOO reflects the loss (or probable loss) of the disjunct subpopulation in Wasaga Beach (see Figure 3, circle with ‘x’ east of Georgian Bay).

Figure 3. Subpopulations of Spotted Wintergreen in Canada. This figure shows all documented subpopulations in Canada to date.
Subpopulations of Spotted Wintergreen in Canada
Photo: © Sources: NHIC 2015, CDPNG 2015.
Long description for Figure 3

Map illustrating the distribution of Spotted Wintergreen subpopulations in Canada, where it occurs in southern Ontario. Almost the entire Canadian population is found in Norfolk County. Extant, extirpated, and historical subpopulations are noted.

In preparation for this status report, 12 sites in four of the known subpopulations (Table 1) were visited by Melinda Thompson between August and October, 2012. Each site was searched for at least one hour, sometimes with multiple observers. Three additional sites in the Turkey Point and Fishers Glen subpopulations were surveyed by Ron Gould in 2012. Population data for one Turkey Point site (2011 survey) were provided by Sam Brinker and Mike Oldham. Survey information for Spooky Hollow ANSI (2011, 2013) was provided by the Hamilton Naturalists’ Club. The estimated 2011-2013 search effort for this species is a minimum of 25 person-hours. The Windsor subpopulation was discovered by Paul Pratt in June 2014.

Several sites, especially within the Turkey Point area, are newly reported in this status report, and reflect substantial increased survey effort over the past decade. Since the last status report, Spotted Wintergreen habitat in the Turkey Point and St. Williams area has been surveyed as a result of local conservation initiatives (e.g., White 2012). It is not possible to quantify this search effort, which has not focused exclusively on Spotted Wintergreen.

Over the past century, many of the remaining natural areas in southwestern Ontario, including the Ojibway Park area, have been well surveyed botanically. The recent discovery of two subpopulations at sites where Spotted Wintergreen was not previously known is somewhat unexpected.

Historical sites (Wasaga Beach and Trout Creek) were not surveyed in preparation for this status report, due to time limitations and the fact that these sites had previously been searched by others unsuccessfully. Searches for Spotted Wintergreen have been undertaken in the Wasaga Beach area by Dan Brunton in 1988 (Brunton 1989), Bob Bowles and others in 1991, 1992, 2000, and 2001 (Bowles 2001). A 1995 observation in Wasaga Beach Park by Heather Stewart was not relocated by Mike Oldham, Wasyl Bakowsky, and Don Sutherland. In the 2001 season, Bowles (2001) and several other botanists comprehensively searched three sites in the Wasaga Beach area and concluded that there were no plants present. Since 2001, Ontario Parks staff have occasionally surveyed the area without locating any plants (Chambers pers. comm. 2015). Still, habitat probably exists at both of the historical sites, and it remains possible that plants could be found there (Oldham pers. comm. 2015). The Trout Creek subpopulation has not been visited since 1997, and nothing is known of its status. Because of the elapse of time, this subpopulation is considered “extirpated” by the NHIC and in the federal recovery strategy for the species (Environment Canada 2015). This may be the case; however, here it is considered “historical” since habitat has not been recently surveyed.

Considering the broad distribution of all documented records from Windsor to Muskoka and potentially into western Quebec, it is possible that other suitable but unsurveyed areas exist, particularly in southcentral Ontario.

Throughout its range, Spotted Wintergreen typically occurs in pine or oak-pine mixed forest and woodland habitats (NatureServe 2015). In Canada, recent and available field observations have confirmed that the species is a woodland understorey species typically associated with dry–fresh oak and oak-pine mixed forests and woodlands (Ursic et al. 2010). These communities typically have semi-closed canopy conditions with an overstorey of Eastern White Pine (Pinus strobus), Red Oak (Quercus rubra), Black Oak (Quercus velutina), and American Beech (Fagus grandifolia), and a groundcover layer of Common Pipsissewa, Partridgeberry (Mitchella repens), Wild Lily-of-the-valley (Maianthemum canadense), Bracken Fern (Pteridium aquilinum) and Wild Sarsaparilla (Aralia nudicaulis). Several patches occur within or on the edges of old plantations consisting of Red Pine (Pinus resinosa) or Eastern White Pine, especially at St. Williams’ Conservation Reserve (Thompson pers. obs. 2012; Heagy pers. comm. 2015).

Spotted Wintergreen subpopulations appear to occur in sites with a relatively narrow (and acidic) pH range, although site-specific information on pH levels is not available. The species prefers an average soil pH below 6 (Eastman 1976; Kirk 1987).

Based on the available information (Ursic et al. 2010), key habitat characteristics for Spotted Wintergreeninclude:

Spotted Wintergreen appears to prefer partially shaded conditions. In North Carolina, Fraver (1994) found that C. maculata increased in percent cover within 10 x 10 m plots towards the edge of an edge-to-interior gradient within deciduous forests. The related Common Pipsissewa reportedly persists in dense shade, but with reduced flowering and fruit-set, and an increase in clonal propagation (Lundell et al. 2015). Plants in dappled as opposed to deep shade appear to bear more flowers (Heagy pers. comm. 2015). There is speculation that canopy closure may have contributed to the decline of one site in the St. Williams Forest subpopulation, although the threshold at which declines may occur is unknown. Further study of light tolerance will be completed at St. Williams Conservation Reserve in 2016 (Heagy pers. comm. 2015).

Spotted Wintergreen probably does not tolerate fire well, although it may benefit from the effects of fire. In a Tennessee study, Zimmerman (2006) found that C. maculata did not persist following prescribed burns at his six study sites. Two related pyroloid species (Chimaphila menziesii, Pyrola picta) reportedly disappeared from plots following prescribed fires in a mixed conifer forest in California (Rocca 2009). Studies in the United States have shown that both C. menziesii and C. umbellata have a moderate to high probability of being killed by fire (Matthews 1994a,b). To date, Spotted Wintergreen has been successfully protected from prescribed burns undertaken at Turkey Point and St. Williams Conservation Reserve. In managed restoration areas of Norfolk County (e.g., Turkey Point Provincial Park and St. Williams), the management approach is to protect Spotted Wintergreen from prescribed burns (Gould pers. comm. 2015).

Spotted Wintergreen is a partial mycoheterotroph, meaning that it depends on the presence of soil mycorrhizae to germinate, develop, and possibly to persist in shaded conditions (see Physiology and Adaptability, below).

Canadian subpopulations of Spotted Wintergreen are situated in areas where sufficient habitat for natural expansion is available in the adjacent environment. Dry-fresh oak and oak-pine mixed forests and woodlands are not uncommon within the species’ range in Ontario, although several of the areas with suitably sandy substrate have been converted to agriculture or plantation. One subpopulation (Ojibway Park) is surrounded by urban development and is limited in extent.

Several aspects of the biology of Spotted Wintergreen remain unclear, including the relative contribution of clonal spread versus recruitment through seeds. Mycorrhizal associations also appear to be important for this species, as they are for many members of the Ericaceae (Massicotte et al. 2008; Johansson and Eriksson 2013).

In southern Ontario, Spotted Wintergreen flowers in mid-July for approximately 17 days. Fruiting tends to occur in August with the capsule splitting and releasing its abundant seeds, many of which persist in the capsule into the next spring (Kirk 1987; Ursic et al. 2010).

As is the case for many clonal plants of the forest understory, there is no information on the generation time of Spotted Wintergreen or related taxa. At a minimum, flowering individuals are probably at least 2-3 years old. However, in clonal plants, genets continually produce new ramets from underground rhizomes and older ramets senesce. Using recent molecular methods, genet longevity in many tree and shrub species has been found to be significantly greater than previously thought. In some clonal shrubs, genet age may range from decades to even thousands of years (de Witte and Stöcklin 2010). Generation time, or the average age of a mature reproductive individual, may be averaged in clonal taxa to account for both asexually and sexually reproducing individuals in the population (IUCN 2010). Generation time for Spotted Wintergreen can be conservatively estimated at a decade, although it could be substantially longer.

The pollination biology of Spotted Wintergreen has been examined by Standley et al. (1988), who studied sympatric populations of Spotted Wintergreen and Common Pipsissewa in a Massachusetts deciduous forest. This study found that the species partially overlap in flowering time (with different peaks in early to mid-July), and are both visited primarily by bumble bees (Bombus species). In this study, Spotted Wintergreen was visited primarily by Confusing Bumble Bee (Bombus perplexus), while Common Pipsissewa was visited by Two-spotted Bumble Bee(B. bimaculatus), Half-black Bumblebee(B. vagans) and Confusing Bumble Bee. Many of the northern European Pyrolaceae are primarily buzz-pollinated by Bombus species, although evidence is conflicting whether plants in the genus Chimaphila are among these (Knudsen and Oleson 1993). No studies have been found that have investigated this question.

Standley et al. (1988) report that Spotted Wintergreen is self-compatible, but pollinator exclosures revealed that they require pollinators for seed set (i.e., they do not regularly self fertilize).

Seeds of species in the tribe Pyroleae (family Ericaceae) are described as “dust seeds” containing minimal nutrient reserves, and, as with orchids, ultimately dependent on fungal symbionts for germination and seedling development (Johansson and Eriksson 2013). Evidence of colonization of roots by fungal mycorrhizal associates has been found in several other members of this tribe, and individual species of ectomycorrhizal fungi are known from several pyroloids, including the congeneric Common Pipsissewa (Zimmer et al. 2007; Massicotte et al. 2008). It can be presumed that Spotted Wintergreen also hosts mycorrhizal associates, although the fungal species remains unknown.

Fungal symbionts likely contribute to nutrient exchange for the developing embryo, and also provide an additional source of nutrition for mature photosynthetic green plants. It has been demonstrated that several pyroloid species from both North America and Europe can gain nitrogen and, to a lesser degree, carbon via mycorrhizal fungi (Tedersoo et al. 2007; Zimmer et al. 2007). The ability to obtain organic nitrogen and carbon through symbionts apparently allows these species to supplement energy provided through photosynthesis, and therefore to tolerate the low levels of sunlight of a shaded forest understorey (Zimmer et al. 2007). It has been proposed that root fungi, particularly ectomycorrhizal fungi, could also link these species to carbon flows from surrounding trees (Tedersoo et al. 2007).

Despite the possible advantages conferred by this partial mycotrophic strategy, pyroloids may also be more sensitive to disturbances, such as logging, anthropogenic nitrogen deposition, or non-native earthworm invasion, which can alter mycorrhizal fungal composition in soils (Hale et al. 2006; Zimmer et al. 2007). In general, mycotrophs have been shown to be sensitive to disturbances, in part because they rely on specific microhabitat features, such as deep litter layers and moisture levels (Halpern and Spies 1995; Lindh and Muir 2004).

Both Spotted Wintergreen and the related Common Pipsissewa are known to be difficult to propagate from seed (Cullina 2000; Pengelly and Bennett 2011), perhaps owing to their association with fungal mycorrhizae.

Spotted Wintergreenis capable of reproducing either vegetatively, or from seed (Standley et al. 1988). Determining the precise number of clones or individuals within a subpopulation would require excavation or genetic analysis, which has yet to be done for this species. Clumps can consist of few to several hundred stems, so a subpopulation consisting of several hundred stems represents an unknown number of genetic individuals (Standley et al. 1988).

The tiny seeds of pyroloids are likely dispersed by wind, and possibly by rain, as the dehisced capsules are appropriately shaped for splash-cup dispersal of seeds (Amador et al. 2013). Although the Canadian population flowers and produces seed regularly, it has been hypothesized that low seed viability and dispersal must be limiting intrinsic factors to population growth, because unoccupied habitat is readily available at most extant sites (Kirk 1987). It is also possible that other, poorly understood factors (e.g., the presence of mycorrhizal fungi) limit germination and establishment.

As described above, Spotted Wintergreen probably depends on mycorrhizal associates, although the species and nature of the association remains unclear (Boullard and Ferchau 1962; Largent et al. 1980; Massicotte et al. 2008).

Spotted Wintergreen is likely mainly pollinated by bumble bees (Standley et al. 1988). Recent widespread declines in abundance of common bumble bee species have been observed throughout North America (Williams et al. 2014). The potential effect of this on Spotted Wintergreen pollination is not known.

Although Common Pipsissewa is known to share Spotted Wintergreen’s range and habitat, even to a microsite level, the two species do not interbreed. It is unclear whether or not the more common species is capable of competitively excluding Spotted Wintergreen (Standley et al. 1988). There are no known herbivores or seed predators for Spotted Wintergreen, though some have been suggested (Ursic et al. 2010).

Each subpopulation was visited for a minimum of one hour during the preparation of this report. Where previously reported plants could not be located, an additional hour was spent searching on a separate day. Stems were counted at all subpopulations. No information was collected on the number or proportion of stems that were flowering; many sites were visited outside the flowering period. At this time, there is no information available to estimate the number of mature individuals this represents.

In the past, reliable, accurate, and current census information on subpopulations of Spotted Wintergreen was incomplete or lacking. Inconsistencies in survey methods as well as the naming and geographical referencing of subpopulations prevented comparative analyses of trends. Recent improvements in quality and frequency of searches have improved the knowledge of the species and enabled a better understanding of the population trends at each extant location.

The current known distribution of Spotted Wintergreen in Canada consists of five extant subpopulations in Ontario (Figure 3) that support a minimum of 3600 Footnote2 stems (Table 1). The total number of mature individuals is not known, but is probably less than this number by an unknown factor. Many, but not all, of these stems (ramets) may flower and become reproductive, Footnote3 although they may also be part of the same genetic individual. No data are available on the percentage of reproductive stems during 2012-2013 surveys. The mean number of stems per genetic individual has not been estimated for Spotted Wintergreen.

Recent discoveries (2010-2016) at St. Williams Conservation Reserve will likely increase this total. Several new sites have been identified at St. Williams during 2014 and 2015 fieldwork (Heagy pers. comm. 2015, 2016). These are considered as new sites within existing subpopulations at St. Williams and Turkey Point. In 2016, most previously known patches were found, and new patches continue to be located (Heagy pers. comm. 2016).

Of the five extant subpopulations (=EOs), the three found in Norfolk County (St. Williams Forest, Turkey Point area, and Fishers Glen area) constitute almost the entire Canadian population. Only 15 stems have been reported between the other two extant subpopulations (i.e., Perry Road Woodlot in Niagara Region, and Ojibway Park in Windsor).

Based on thorough fieldwork, Bowles (2001) concludes that the Wasaga Beach subpopulation, including one well-documented site and two credible reports, is likely no longer extant. He suggests that this could be due to successional changes in the habitat. Opinion differs on the likelihood of rediscovering Spotted Wintergreen at Wasaga Beach. Although some habitat is present at both historical subpopulations, plants have only ever been observed in small number (i.e., fewer than 10 plants each), and even their rediscovery is unlikely to significantly change the total Canadian abundance.

It is difficult to quantify trends in abundance with confidence. Most early counts (pre-2000) refer to “plants” rather than “stems,” and may not be comparable with later surveys. Survey effort has also increased, especially in Norfolk County.

Totals for the Canadian subpopulations were not provided in previous status reports (Kirk 1987; COSEWIC 2000) due to limited survey data, but they were certainly much lower (i.e., a few hundred “plants”). In the more recent Ontario Recovery Strategy, Ursic et al. (2010) report approximately 2700 stems, based on 2007 surveys of a similar number of subpopulations (excluding Turkey Point Provincial Park and the Windsor subpopulation).

A review of stem counts at all subpopulations (see Table 1) also suggests that the Canadian population has increased somewhat since about 2000, when more detailed and standardized counts became available. Although some sites have not been relocated in recent surveys, abundance at others, such as the Nursery Tract at St. Williams Forest, appears to have substantially increased since 2000. The reasons for this are not known, but could be related to increased light penetration at some sites. This may be the result of any of several factors, including canopy thinning, prescribed burning, defoliation by European Gypsy Moth (Lymantria dispar dispar), and the establishment of the Emerald Ash Borer (Agrilis planipennis) (Gould pers. comm. 2015). Substantial increases in stem counts at one site (Nursery Tract) have followed the closure of ATV and horse trails to the area.

Two subpopulations, and several new sites within the other three subpopulations, have been discovered since the 2000 status report. This should be interpreted cautiously. Although it is possible that these sites have become established and that the population of Spotted Wintergreen is increasing, most recent discoveries probably reflect increased survey effort and reporting, particularly in Norfolk County. Some are probably rediscoveries of older records, thought to be extirpated. The recently discovered Ojibway Park subpopulation in Windsor is one exception. This well-known natural area has been extensively botanized over many decades, and the discovery of a fairly conspicuous species next to a trail was unexpected. It is possible that this subpopulation was recently established (Oldham pers. comm. 2015).

The Parc national d’Oka site in Quebec is newly reported in this status report. This subpopulation consisted of one plant (two stems) when it was discovered in 1992. Following unsuccessful surveys in 2002 and 2006, it is now presumed extirpated. The cause of the disappearance is unclear, because suitable areas of habitat remain, and threats are believed to be low (Centre de données sur le patrimoine naturel du Québec 2015). It is considered likely to be an unsuccessful introduction.

The Canadian population of Spotted Wintergreen does not exhibit “extreme fluctuations” in population abundance.

Across the species’ American range, populations are apparently relatively stable, with no major declines reported (NatureServe 2015). In the adjacent northern states of Maine and Vermont, populations appear to be increasing, with recent new reports; however, Spotted Wintergreen may also have been under-reported in the past (Cameron pers. comm. 2015; Popp pers. comm. 2015).

The likelihood of natural colonization of Spotted Wintergreen from the United States is possible, especially in extreme southwestern Ontario. The species has been reported from three counties in adjacent Michigan (Reznicek et al. 2011), within perhaps 50-100 km of the newly discovered Windsor site. Although dust seeds are able to remain airborne for long periods of time, and may travel long distances, the vast majority are deposited within a few metres of the seed source (Arditti and Ghani 2000; Johansson et al. 2014). It is plausible that the Windsor subpopulation may have become established recently from an U.S. source.

Other populations in the United States occur more distantly to the south, across lakes Erie and Ontario. Spotted Wintergreen has been documented in northern Ohio (SNR, not ranked) and New York (S4, apparently secure) (NatureServe 2015). Sites in Vermont and Maine are restricted to the southern portions of these states, at least 200 km from Quebec (Kartesz 2015; Popp pers. comm. 2015).

The IUCN threats calculator (Master et al. 2012) was used to assess threats to Spotted Wintergreen (Appendix 1). The threats calculator method consists of scoring the scope, severity, and timing for each standard threat category; the overall threat impact is then computed from these ratings.

The assigned overall threat impact for Spotted Wintergreen is Medium – Low. The combination of two separate Low impact threats and two Medium – Low impact threats resulted in an overall calculated threat impact of High – Medium. However, because each of the threat impacts was deemed to be at the low end of the range, this calculated rank was adjusted to Medium – Low (Appendix 1).

Headings in the following narrative correspond to categories or subcategories of the threats calculator, in the approximate order of their perceived importance.

Disturbance associated with recreational activities probably constitutes the main threat to Spotted Wintergreen. This includes impacts from ATV use, mountain biking, horseback riding, and hiking. The majority of sites are located on public land. Several of these (e.g., sites in St. Williams Conservation Reserve and at Turkey Point Provincial Park) are accessible to ATVs and/or mountain bikes, and several patches lie in close proximity to active trails (Gould pers. comm. 2015). Similar threats by ATV use have been noted in past reports (Kirk 1987; COSEWIC 2000; White 2010). Kirk (1987) noted that ATV use may have resulted in the extirpation of the Simcoe subpopulation. One Turkey Point site was not relocated in 2012, and may have been lost to ATV use (Thompson pers. obs. 2012).

The risk to Spotted Wintergreen and other species at risk within the St. Williams Conservation Reserve and Turkey Point Provincial Park is decreasing, as unauthorized trails are closed and rehabilitated, and monitoring has increased (Gould pers. comm. 2015; Heagy pers. comm. 2015). Still, it is difficult to monitor and enforce trails in such a large area with significant recreational pressure, and closing trails has proven difficult (Gould pers. comm. 2015). Many sites (e.g., in St. Williams, Turkey Point, Ojibway Park) are near walking trails and could be affected by trampling or soil compaction.

Abundant native species such as White-tailed Deer (Odocoileus virginianus) and reintroduced Wild Turkey (Meleagris gallopavo) may browse or excavate populations of Spotted Wintergreen. Recently, a patch of Spotted Wintergreen disappeared overnight at the Spooky Hollow site and is thought to have been browsed by White-tailed Deer. An exclosure has since been placed over the patch, which has effectively protected the small population (Beck pers. comm. 2016). Foraging by Wild Turkey has caused forest floor disturbance at the St. Williams site (Gould 2001). Scratching and uprooting behaviour of Wild Turkeys could damage rhizomes of Spotted Wintergreen (Gould pers. comm. 2015), although direct evidence of this has not been observed.

The suppression of fire, and resulting natural succession leading to shaded conditions, may threaten Spotted Wintergreen. Shadier sites appear correlated with decreases in flowering in Common Pipsissewa, and natural succession is implicated in its decline in Europe (Lundell et al. 2015). Some Ontario Spotted Wintergreen sites at a later successional stage (e.g., Fisher’s Glen) may not be thriving; observations over 15 years in Ontario suggest that Spotted Wintergreen colonies often benefit when light levels increase, such as following localized blowdowns or canopy defoliation (Gould pers. comm. 2015). Still, colonies of Spotted Wintergreen appear to persist for long periods of time at shadier sites and are able to reproduce vegetatively. The effects of light levels and/or natural succession on Spotted Wintergreen have not been studied.

Due to the accumulation of thick leaf litter, high-intensity natural wildfire can break out in areas where fire has previously been suppressed. Such high-intensity fires may also threaten this species, because it is not believed to be fire-tolerant (Zimmerman 2006; Gould pers. comm. 2015).

Although widespread land clearance has occurred within this species’ range in the past, loss of habitat to land development or agriculture is probably now a minor threat. Most extant sites are found on land that is either publicly owned, or owned by conservation organizations, and guided by management plans. These are protected in varying degrees from development. Two sites are believed to be privately owned (Table 1). Either site could be inadvertently destroyed, especially if owners are unaware of the presence of the species on the property.

Forestry was probably a significant threat in the past. In New England, Duguid et al. (2013) found that C. maculata abundance declined following timber harvest and soil scarification within study plots. It has been shown that the related Common Pipsissewa and two other mycotrophs decreased in frequency following forest thinning treatments (Davis and Puettman 2015). Logging occurred at one of the two privately owned sites about a decade ago, and Ontario Ministry of Natural Resources and Forestry (OMNRF) district office staff were consulted to ensure protection of the Spotted Wintergreen population (Gould pers. comm. 2015). Although no formal monitoring has occurred, the number of stems observed at this site appears to have remained constant.

Few invasive plant species have been reported from Spotted Wintergreen habitat (Thompson pers. obs. 2012; Oldham pers. comm. 2015). One newly discovered site at St. Williams Conservation Reserve occurs underneath a large and spreading patch of Little-leaved Linden (Tilia cordata). Other invasive species near some Norfolk County sites include Spotted Knapweed (Centaurea stoebe ssp. micranthos), Multiflora Rose (Rosa multiflora), and Garlic Mustard (Alliaria petiolata) although to date these have not invaded occupied Spotted Wintergreen habitat (Gould pers. comm. 2015; Heagy pers. comm, 2015).

Non-native, invasive insects may have an effect on Spotted Wintergreen, although it is not clear whether this constitutes a threat. Changes in forest light levels, caused by the death of ash trees due to the Emerald Ash Borer and defoliation by the European Gypsy Moth, may be beneficial at some shaded sites, but detrimental in other cases (Gould pers. comm. 2015). Hemlock Woolly Adelgid (Adelges tsugae) has also been found to result in losses of Spotted Wintergreen in North Carolina (Ford et al. 2012). Although not yet present in Spotted Wintergreen range, Hemlock Woolly Adelgid has been found in southern Ontario and is expected to spread (Canadian Forest Service 2013).

Garbage dumping has been observed at the Wainfleet site (Ursic et al. 2010), and sometimes occurs along trails and roadsides in St. Williams Conservation Reserve (Heagy pers. comm. 2016). Unauthorized dumping could occur at any site, regardless of ownership. Although such degradation may be localized, several subpopulations occupy only a few square metres, and elimination of an entire subpopulation is possible.

Almost all Spotted Wintergreen sites are now on land managed for conservation purposes. In particular, the former St. Williams provincial tree nursery, largely consisting of plantation pine, is now managed as a Conservation Reserve, and is being restored to oak-pine savanna habitat through thinning of plantation pines. Restoration work is guided by biologists with expertise in vegetation management following a management plan, and the maintenance and/or restoration of Species at Risk habitat is a primary consideration (White 2010). Currently, thinning does not occur within 30 m of Spotted Wintergreen habitat. In 2016, surveys of extant Spotted Wintergreen sites will be used to develop management recommendations to guide future plantation thinning and oak savanna restoration (Heagy pers. comm. 2015). In contrast to Logging and Wood Harvesting, and Wildfire, habitat management techniques such as canopy thinning and prescribed burning are not believed to threaten Spotted Wintergreen because their use is carefully controlled and monitored.

Climate warming may affect this species, although it is uncertain whether this will have a positive or negative effect on Spotted Wintergreen. In an experimental study in North Carolina, Marchin (2014) found that a 2°C summer warming resulted in reproductive failure in Spotted Wintergreen. Probable effects of climate change, such as elevated CO2 levels, drought, and increased temperatures, can also alter the abundance of mycorrhizal fungi and their interactions with host plants in a variety of ways (Drigo et al. 2008; Compant et al. 2010). However, Spotted Wintergreen ranges into Central America. Several new reports of Spotted Wintergreen in Ontario, Vermont, and Maine suggest that it is not currently decreasing at the northern edge of its range and may be increasing (Cameron pers. comm. 2015; Popp pers. comm. 2015).

Because mycorrhizal fungi appear to be an obligate associate of pyroloid species, pollution that changes fungal composition and abundance could have an impact on associated vascular plants. Pyroloid plants are known to be sensitive to increases in atmospheric nitrogen deposition, which is associated with a reduction in fungal diversity (Wallenda and Kotke 1998). Other forms of pollution have been found to alter the diversity and species composition of forest mycorrhizal fungi (Arnolds 1991; Peter et al. 2001). It is unknown whether this affects Canadian subpopulations.

Non-native earthworms are considered invasive across eastern North America and have been shown to have considerable impacts to the forest understory and plant composition (Hale et al. 2006, 2008). It is possible but unknown whether earthworms are present in the dry forest and woodland habitats where Spotted Wintergreen has been found.

Although there has been evidence of collection in the past (White 1998 cited in Ursic et al. 2010), it is not currently considered to be a significant threat (Gould pers. comm. 2015). No evidence of collection has been observed for many years, despite detailed work on the species, and the market value of this species as a medicinal plant is reportedly low (NatureServe 2015).

Spotted Wintergreen’s dependence on fungal hosts to complete germination and development may limit populations, especially the establishment of new colonies. For the related Common Pipsissewa and several other pyroloids, microsite availability was found to be an important limiting factor for plant recruitment (Johannson and Eriksson 2012).

Several threats occur in the area occupied by this species, but the threat affecting the largest proportion of the population is likely fire. Recreation activities and impacts by deer and turkey are localized and are unlikely to rapidly affect a large proportion of the population. Although its overall impact is low based on a threat assessment, fire appears to be the most significant plausible threat. Although the number of forest patches where this species occurs are few, they all occur in a rural landscape, with some in Provincial Parks or Conservation Areas, so firefighting response is likely to be rapid. It seems reasonable to assume a limited area would be impacted in any one fire; how large an area is unknown. Because of the uncertainty involved, a range in the number of locations is probably appropriate.

For this report, Canadian “subpopulations” are considered to be synonymous with element occurrences Footnote4. The Ontario element occurrences have been recently re-analyzed (Craig pers. comm. 2015), and some subpopulations that were previously separate (e.g., several in Norfolk County, especially at St. Williams Forest and Turkey Point) have been consolidated. There are presently five extant element occurrences (EOs), with about 19 known sites overall. Note that this breakdown of EOs and subpopulations has been updated from those in previously published recovery strategies (Ursic et al. 2011; Environment Canada 2015).

Two of the EOs, Ojibway Park and Perry Road, each consist of only one patch of plants with a small number of individuals, so they comprise two locations. The other three EOs have multiple sites. The known sites within St. Williams Forest EO extend about 1.3 km north to south, and about 600 m east to west, with most of the subpopulation at one site. This EO could be considered one or two locations, as wildfire extending over a kilometre is possible but unlikely. The known sites at Turkey Point extend over 3 km east to west and about 2 km north to south. One site is separated from the others by over a kilometre (Turkey Point Tract F), so it could be one location. Using the assumption that a fire is unlikely to extend over several kilometres, the rest of this EO is two or more locations. Assuming two locations for Turkey Point, plus one for Turkey Point Tract F, results in 2-3 locations for the entire Turkey Point area. The Fishers Glen EO extends over 2.7 km east to west, with 1.7 km between two known sites. Two locations seem reasonable here, based on the distance between sites. The plausible range of locations for Spotted Wintergreen in Canada is considered to be 7-9 assuming that wildfire is the most significant plausible threat and making assumptions on fire response.

Spotted Wintergreen was first assessed by COSEWIC in 1987 as Endangered. This status was re-examined and confirmed in 1998 and 2000. The species was listed on Species at Risk Act (SARA)Schedule 1 as Endangered in 2004. The species is also listed as Endangered in Ontario under the Endangered Species Act, 2007, and a provincial Recovery Strategy has been finalized (Ursic et al. 2010). Under the ESA, the species and its habitat in Ontario receive protection. A federal addition to the provincial recovery strategy has also identified critical habitat for this species under the federal SARA (Environment Canada 2015).

NatureServe (2015) ranks Spotted Wintergreen as G5 (secure; last reviewed in 2001). The species is ranked N5 (secure) in the United States and N2 (imperiled) in Canada. The species is ranked S2 (imperiled) in Ontario and SX (presumed extirpated) in Quebec. In the U.S., subnational ranks for Spotted Wintergreen include: S1 – critically imperiled (Illinois), S2 – Imperiled (Maine, Vermont and Mississippi), S3 – vulnerable (Indiana and Arizona), S4 – apparently secure (New York), and S5 – secure (New Jersey, Delaware, District of Columbia, Virginia, West Virginia, Kentucky and North Carolina). It is not ranked in the remaining 13 states in which it occurs.

Of the five extant subpopulations, four are found entirely or mostly on publicly owned lands (i.e., Crown Land, Provincial Parks or Conservation Areas). These areas are protected from development, although they may be subject to numerous other disturbances including ATV use and trampling. A portion of the Turkey Point subpopulation (Normandale site) is privately owned and is operated as a children’s summer camp. The Niagara Region subpopulation occurs on private land, which could be subject to development.

Del Meidinger (Vascular Plants SCC Co-chair), the Vascular Plants SSC, and many jurisdictional reviewers are thanked for providing comments on drafts. Many thanks to Alain Filion of the COSEWIC Secretariat for creating maps and calculating the IAO and EOO. Robert Craig at the Ontario NHIC provided updated element occurrence data and explanation.

Thanks are offered to the following individuals for providing information helpful to the development of this document:

Amador, G.J., Y. Yamada, M. McCurley, and D.L. Hu. 2013. Splash-cup plants accelerate raindrops to disperse seeds. Journal of the Royal Society Interface. 10:20120880

Angelo, D., and D.E. Boufford 2016. Atlas of the Flora of New England [accessed November 5, 2016].

Arditti, J., and A.K.A. Ghani. 2000. Numerical and physical properties of orchid seeds and their biological implications. Tansley Review No. 110. New Phytologist 145:367-421.

Arnolds, E. 1991. Decline of ectomycorrhizal fungi in Europe. Agriculture, Ecosystems and Environment 35:209–244.

Barrett, S.C.H., and K. Helenurm. 1987. The reproductive biology of boreal forest herbs: I. Breeding systems and pollination. Canadian Journal of Botany 65(10):2036-2046.

Beck, G., pers. comm. 2016. Email correspondence to H. Bickerton. March 2016. Acting Ontario Program Manager, Bird Studies Canada, Port Rowan, Ontario.

Boullard, B., and H.A. Ferchau. 1962. Endotrophic mycorrhizae of plants collected in some eastern American and Canadian white pine communities. Phyton, Vincente Lopez 19:65-71.

Bowles, B. 2001. Field Survey Report on the Status of Spotted Wintergreen (Chimaphila maculata) at three Wasaga Beach Provincial Park Sites. Bowles Environmental. Produced for Ontario Parks. 7 pp.

Brunton, D.F. 1989. Biological Inventory and Evaluation Of Wasaga Beach Provincial Park and Adjacent Natural Areas, Simcoe County, Ontario. Ontario Ministry of Natural Resources, Central Region, Richmond Hill. OFER 8905. ix + 166 pp. + maps.

Cameron, D.S., pers. comm. 2015. Email correspondence to H. Bickerton. September 2015. Botanist/Ecologist, Maine Natural Areas Program, Augusta, Maine.

Canadian Forest Service. 2014. Alien, invasive hemlock woolly adelgid found in Ontario (PDF Version; 475 KB). Frontline : Forestry Research Applications. Technical Note No. 114.

Centre de données page sur le patrimoine naturel du Québec (CDPNG). 2015. Chimaphila maculata occurrence report. 5 pp.

Chambers, Jennifer, pers. comm. 2015. Email correspondence to H. Bickerton. September 2015. Assistant Ecologist, Ontario Parks, Southwest Zone, Ontario Ministry of Natural Resources and Forestry, London, Ontario.

Compant, S., M.G. Van Der Heijden, and A. Sessitsch. 2010. Climate change effects on beneficial plant–microorganism interactions. FEMS Microbiology Ecology 73:197-214.

COSEWIC 2000. COSEWIC assessment and update status report on the spotted wintergreen Chimaphila maculata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 6 pp.

COSEWIC. 2014. Guidelines for recognizing designatable units. [accessed November 10, 2015].

Craig, R., pers. comm. 2015. Email correspondence to H. Bickerton. November 1999. Species at Risk Analyst, Natural Heritage Information Centre Ontario Ministry of Natural Resources and Forestry, Peterborough, Ontario.

Cullina, W. 2000. New England Wildflower Society Guide to Growing and Propagating Wildflowers of the United States and Canada. Houghton Mifflin, New York, NY.

Davis, L.R., and K.J. Puettmann. 2009. Initial response of understory vegetation to three alternative thinning treatments. Journal of Sustainable Forestry 28(8):904-934.

de Witte, L.C., and J. Stöcklin. 2010. Longevity of clonal plants: why it matters and how to measure it. Annals of Botany 106:859-870.

Drigo, B., G.A. Kowalchuk, and J.A. van Veen. 2008. Climate change goes underground: effects of elevated atmospheric CO2 on microbial community structure and activities in the rhizosphere. Biology and Fertility of Soils 44:667-679.

Duguid, M.C., B.R. Frey, D.S. Ellum, M. Kelty, and M.S. Ashton. 2013. The influence of ground disturbance and gap position on understory plant diversity in upland forests of southern New England. Forest Ecology and Management 303:148-159.

Eastman, L.M. 1976. Spotted Wintergreen, Chimaphila maculata (L.) Pursh in Maine and its Relevance to the Critical Areas Program. Planning Report No. 21, State Planning Office, Maine Critical Areas Planning Program, Augusta, Maine.

Environment Canada. 2015. Recovery Strategy for the Spotted Wintergreen (Chimaphila maculata) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. 24 pp. + Appendix.

Ford, C.R., K.J. Elliott, B.D. Clinton, B.D. Kloeppel, and J.M. Vose. 2012. Forest dynamics following eastern hemlock mortality in the southern Appalachians. Oikos 121:523-336.

Fraver, S. 1994. Vegetation Responses along Edge-to-Interior Gradients in the Mixed Hardwood Forests of the Roanoke River Basin, North Carolina. Conservation Biology 8(3):822-832.

Freeman, C.C. 2009. Chimaphila In: Ericaceae. Flora of North America North of Mexico: Volume 8 Magnoliophyta: Paeoniaceae to Ericaceae. Oxford University Press. New York. Pp. 385-387.

Gould, R. 2001. Spotted Wintergreen (Chimaphila maculata) 2001 Survey Report. Unpublished Report.

Gould, R., pers. comm. 2015. Email correspondence to H. Bickerton. September 2015. Resource Steward, Ontario Parks Southwest Zone, Ontario Ministry of Natural Resources, London, Ontario.

Haber, E., and C.J. Keddy. 1984. Chimaphila maculata (L.) Pursh. A page in the Atlas of the Rare Vascular Plants of Ontario, Part 3, Eds. G. W. Argus and C. J. Keddy, National Museum of Canada, Ottawa.

Hale, C.M., L.E. Frelich, and P.B. Reich. 2006. Changes in hardwood forest understory plant communities in response to European earthworm invasions. Ecology 87:1637-1649.

Hale, C.M., L.E. Frelich, P.B. Reich, and J. Pastor. 2008. Exotic earthworm effects on hardwood forest floor, nutrient availability and native plants: a mesocosm study. Oecologia 155:509-518.

Halpern, C.B., and T.A. Spies. 1995. Plant species diversity in natural and managed forests of the Pacific Northwest. Ecological Applications 5:913–934.

Heagy, A., pers. comm. 2015. Email and telephone correspondence with H. Bickerton. September 2015. Chair, St. Williams Conservation Reserve Community Council, Ontario.

Heagy, A. 2016. Personal Communication. Email correspondence with H. Bickerton. November 2016. Chair, St. Williams Conservation Reserve Community Council, Ontario.

Hynson, N.A., K. Preiss, G. Gebauer, and T.D. Bruns. 2009. Isotopic evidence of full and partial myco-heterotrophy in the plant tribe Pyroleae (Ericaceae). New Phytologist 182:719-726.

IUCN 2010. Guidelines for Using the IUCN Red List Categories and Criteria (PDF Version). Version 8.1. Prepared by the Standards and Petitions Subcommittee in March 2010.

Jacobs, D. 2001. Spotted Wintergreen: Chimaphila maculata at Parc D’Oka, Quebec. Unpublished Report.

Johansson, V.A., and O. Eriksson. 2013. Recruitment limitation, germination of dust seeds, and early development of underground seedlings in six Pyroleae species. Botany 91:17-24.

Johansson, V.A., G. Müller, and O. Eriksson. 2014. Dust seed production and dispersal in Swedish Pyroleae species. Nordic Journal of Botany 32:209-214.

Kartesz, J. T. 2015. The Biota of North America Program (BONAP). North American Plant Atlas. Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2015. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]. [accessed: September 18, 2015].

Kirk, D. 1987. COSEWIC status report on the Spotted Wintergreen Chimaphila maculata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 36 pp.

Knudsen, J.T., and J.M. Oleson. 1993. Buzz-pollination and patterns in sexual traits in north European Pyrolaceae. American Journal of Botany 80(8):900-913.

Labrecque, J., pers. comm. 2015. Email correspondence to H. Bickerton. April and November 2015. Botanist, Ministère du Développement durable, de l'Environnement et de la Lutte contre les Changements Climatiques, Québec.

Largent, D.L., N. Sugihara, and C. Wishner. 1980. Occurrence of mycorrhizae on ericaceous and pyrolaceous plants in northern California. Canadian Journal of Botany 58:2274-2279.

Lindh, B.C., and P.S. Muir. 2004. Understory vegetation in young Douglas-fir forests: Does thinning help restore old-growth composition? Forest Ecology and Management 192:285–296.

Liu, Z.W., Q.R. Zhao, and J. Zhou. 2013. A test of four candidate barcoding markers for the identification of geographically widespread Chimaphila species (Pyroleae, Ericaceae). Acta Botanica Gallica 160(1): 11-17.

Lundell, A., S.A. Cousins, and O. Eriksson. 2015. Population size and reproduction in the declining endangered forest plant Chimaphila umbellata in Sweden. Folia Geobotanica 1-11.

Marchin, R.M. 2013. Using a physiological approach to improve predictions of climate change effects on temperate forests. North Carolina State University.

Massicotte, H., L. Melville, L. Tackaberry, and R. Peterson. 2008. A comparative study of mycorrhizas in several genera of Pyroleae (Ericaceae) from western Canada. Botany 86:610-622.

Master, L.L., D. Faber-Langendoen, R. Bittman, G.A. Hammerson, B. Heidel, L. Ramsay, K. Snow, A. Teucher, and A. Tomaino. 2012. NatureServe conservation status assessments: factors for evaluating species and ecosystems at risk. NatureServe, Arlington, VA.

Matthews, Robin F. 1994a. Chimaphila menziesii. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [accessed November 4, 2016].

Matthews, Robin F. 1994b. Chimaphila umbellata. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [accessed November 4, 2016].

Moerman, D.E. 2009. Native American medicinal plants: an ethnobotanical dictionary. Timber Press, Portland, Oregon.

Natural Heritage Information Centre. 2015. Element Occurrence Database.

NatureServe. 2015. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. [accessed: November 21, 2015].

Oldham, M.J., pers. comm. 2015. Email correspondence to H. Bickerton, September 2015. Botanist, Natural Heritage Information Centre, OMNRF.

Pengelly, A., and K. Bennett. 2011. Appalachian plant monographs: Chimaphila umbellata (L.) Nutt. Pipsissewa. [accessed: September 18, 2015].

Peter, M., F. Ayer, and S. Egli. 2001. Nitrogen addition in a Norway spruce stand altered macromycete sporocarp production and below-ground ectomycorrhizal species composition. New Phytologist 149(2):311-325.

Popp, B., pers. comm. 2015. Email correspondence to H. Bickerton. August 2015. Department Botanist, Vermont Department of Fish and Wildlife, Natural Heritage Inventory.

Reznicek, A.A, E. G. Voss, and B.S. Walters. 2011. Michigan Flora Online - Chimaphila maculata. University of Michigan. [accessed: September 18, 2015].

Rocca, M. 2009. Fine-scale patchiness in fuel load can influence initial post-fire understory composition in a mixed conifer forest, Sequoia National Park, California. Natural Areas Journal 29(2):126-132.

Sabourin, André, pers. comm. 2015. Email correspondence to H. Bickerton. November 2015. Consulting botanist, Quebec.

Standley, L.A., S. S.-H. Kim, and I.M. Hjersted. 1988. Reproductive biology of two sympatric species of Chimaphila. Rhodora 90:233-244.

Tedersoo, L., P. Pellet, U. Koljalg, and M.-A. Selosse. 2007. Parallel evolutionary paths to mycoheterotrophy in understorey Ericaceae and Orchidaceae: ecological evidence for mixotrophy in Pyroleae. Oecologia 151:206-217.

Ursic, K., T. Farrell, M. Ursic, and M. Stalker. 2010. Recovery strategy for the Spotted Wintergreen (Chimaphila maculata) in Ontario. Ontario Recovery Strategy Series. Prepared for the Ontario Ministry of Natural Resources, Peterborough, Ontario. vi + 28 pp.

Wallenda, T., and I. Kottke. 1998. Nitrogen deposition and ectomycorrhizas. New Phytologist 139:169–187.

White, D.J. 1998. Update COSEWIC status report on spotted wintergreen Chimaphila maculata in Canada. Committee on the Status of Endangered Wildlife in Canada.Ottawa. 1-6 pp.

White, D.J. 2010. Species at Risk Survey at the St. Williams Conservation Reserve. Unpublished report to the St. Williams Conservation Reserve Community Council. December 2010.

Williams, P.H., R.W. Thorp, L.L. Richardson, and S.R. Colla. 2014. Bumble Bees of North America: An Identification Guide. Princeton: Princeton University Press. 208 pp.

Zimmer, K., N.A. Hynson, G. Gebauer, E.B. Allen, M.F. Allen, and D.J. Read. 2007. Wide geographical and ecological distribution of nitrogen and carbon gains from fungi in pyroloids and monotropoids (Ericaceae) and in orchids. New Phytologist 175:166-175.

Zimmerman, M. L. 2006. The Effects of Prescribed Fire on the Herbaceous Layer in the Southern Appalachian Mountains. M.Sc. Thesis, Department of Biological Sciences, East Tennessee State University.

Holly Bickerton is a biologist with over 15 years of experience in southern Ontario. Holly holds a BASc from McMaster University and a Masters in Environmental Studies from York University. She has worked in ecology and species at risk for the Ontario Ministry of Natural Resources and the Department of Environment and Heritage in South Australia. Since 2005, she has worked as an independent consulting ecologist. Holly conducts flora and fauna inventories, vegetation mapping, invasive species assessments, ecological monitoring, and policy research. She has previously authored two COSEWIC status reports, and many other documents on rare and at-risk species.

Melinda Thompson has completed a Master’s thesis on Bird’s-foot Violet (Viola pedata L.), examining optimal microhabitat characteristics in Ontario tallgrass prairie remnants. In addition to completing her MSc, she has been involved in numerous Species at Risk projects with the Ontario Ministry of Natural Resources as a Species at Risk Biologist. Over the past 13 years, she has authored or co-authored reports related to species management and recovery in Ontario and Canada for 9 different plant species. She sits on several Recovery Teams, and has extensive experience working with rare species in Ontario.

No collections were examined in the preparation of this report.

Overall threat impact calculation help:
Threat impact Threat impact (descriptions) Level 1 Threat impact counts:
high range
Level 1 Threat impact counts:
low range
A Very high 0 0
B High 0 0
C Medium 2 0
D Low 2 4
- Calculated overall threat impact: High Medium
Threat table
Threat Id Threat description Impact (calculated) Impact description (calculated) Scope (next 10 Yrs) Severity (10 Yrs or 3 Gen.) Timing Comments
1 Residential & commercial development D Low Small (1-10%) Serious - Slight (1-70%) Moderate (Possibly in the short term, < 10 yrs) blank
1.1 Housing & urban areas D Low Small (1-10%) Serious - Slight (1-70%) Moderate (Possibly in the short term, < 10 yrs) Two private sites are 4.8% of population. Severity is variable, depending upon activity. Timing is possible but not necessarily ongoing. Sites are mostly rural and the one site close to a development is an occasionally used camp. If camp sold, could be developed, especially along lakeshore. NOTE Scope is closer to the 1% range of this estimate.
1.2 Commercial & industrial areas blank blank blank blank blank blank
1.3 Tourism & recreation areas blank blank blank blank blank blank
2 Agriculture & aquaculture blank blank blank blank blank blank
2.1 Annual & perennial non-timber crops blank blank blank blank blank blank
2.2 Wood & pulp plantations blank blank blank blank blank blank
2.3 Livestock farming & ranching blank blank blank blank blank blank
2.4 Marine & freshwater aquaculture blank blank blank blank blank blank
3 Energy production & mining blank blank blank blank blank blank
3.1 Oil & gas drilling blank blank blank blank blank blank
3.2 Mining & quarrying blank blank blank blank blank blank
3.3 Renewable energy blank blank blank blank blank blank
4 Transportation & service corridors blank blank blank blank blank blank
4.1 Roads & railroads blank blank blank blank blank blank
4.2 Utility & service lines blank blank blank blank blank blank
4.3 Shipping lanes blank blank blank blank blank blank
4.4 Flight paths blank blank blank blank blank blank
5 Biological resource use blank Negligible Negligible (<1%) Serious - Slight (1-70%) Moderate (Possibly in the short term, < 10 yrs) blank
5.1 Hunting & collecting terrestrial animals blank blank blank blank blank blank
5.2 Gathering terrestrial plants blank Negligible Negligible (<1%) Serious - Slight (1-70%) Moderate (Possibly in the short term, < 10 yrs) Evidence of collection in past; not considered a current threat. Showy attractive plant but difficult to cultivate.
5.3 Logging & wood harvesting blank Negligible Negligible (<1%) Unknown High (Continuing) Scope is perhaps negligible as <5% private but one of these logged in past 10 years. Impact of logging 10 yrs ago negligible. It is possible that selective harvest is not a threat, but in fact opens the canopy and can stimulate flowering. It has not been demonstrated, and this is why SWCR follows a recommendation not to thin within 30m. May be beneficial and promote flowering (western spp. have an alternate mode & don't necessarily benefit). A study by Jenny McCune that looked at predicted sites to see whether Spotted Wintergreen was there or not found that sites without plants were associated with high shrub cover of species that respond to increased light (spicebush and Sambucus). Canopy gaps created by logging may have adverse effects due to increased shrub cover, but this is speculative at this point. One area is in a woodlot, also logging may occur on private lands. Church camp site is aware of the species and did not mention any logging plans summer 2016. Wainfleet site is also aware of the plant. NOTE: thinning for conservation at St. Williams will be considered under 7.3. Further prescribed burns at this location will be considered under 7 as well.
5.4 Fishing & harvesting aquatic resources blank blank blank blank blank blank
6 Human intrusions & disturbance CD Medium - Low Restricted (11-30%) Moderate - Slight (1-30%) High (Continuing) blank
6.1 Recreational activities CD Medium - Low Restricted (11-30%) Moderate - Slight (1-30%) High (Continuing) Impacts from ATV use, mountain biking, horseback riding and hiking. Plant is small; there is potential from mortality from some of these activities, although many sites are away from trails. Risk decreasing where unauthorized trails closed and rehabilitated--but closure not always successful. Scope is potentially large but severity unknown--used range. St Williams: some plants close to trails at some sites. One site at Ojibway park is within 1m of the trail. If there is mowing or any modifications to the trail, e.g., widening, this would have impacts.
6.2 War, civil unrest & military exercises blank blank blank blank blank blank
6.3 Work & other activities blank blank blank blank blank Research activities were discussed but as overall impacts very low to neutral, it was not scored.
7 Natural system modifications D Low Restricted - Small (1-30%) Moderate - Slight (1-30%) High (Continuing) blank
7.1 Fire & fire suppression D Low Restricted - Small (1-30%) Moderate - Slight (1-30%) High (Continuing) Wildfires and fire suppression and subsequent increased shading may impact colonies; however, vegetative reproduction may allow subpopulations to persist. Observations indicate that colonies benefit when light levels increase, e.g., defoliation or local blowdown. Uncertainty in proportion of population potentially impacted. Fire suppression is ongoing, but fires have been recorded each year (have been quickly put out in the past--Forest patches are near populated areas). Turkey Point and St. Williams both undergo prescribed burning. This species is not very resistant to fire. Input from Ron Gould (OMNR): there should also be consideration that opening up conditions too much from high intensity or frequency of fires would not generally be consistent with preferred habitat within its range, and could favour the growth of herbaceous competition.
7.2 Dams & water management/use blank blank blank blank blank blank
7.3 Other ecosystem modifications blank Not a Threat Large (31-70%) Neutral or Potential Benefit High (Continuing) Habitat restoration, i.e., thinning and prescribed burning for conservation at St. Williams and Turkey Point. This species is considered in habitat restoration work at both sites. Potential impact of introduced earthworms to soil conditions was discussed but thought that majority of sites may be too dry to consider - impact may be unknown but potentially negative.
8 Invasive & other problematic species & genes CD Medium - Low Pervasive - Large (31-100%) Moderate - Slight (1-30%) High (Continuing) blank
8.1 Invasive non-native/alien species blank Unknown Small (1-10%) Unknown High (Continuing) Restricted in area and no real evidence of impact. Invasive plants present in areas, but very low incidence at sites surveyed; dry sandy soils not easily invaded; mountain bike trails at some sites may encourage invasives; probably >1% scope.
8.2 Problematic native species CD Medium - Low Pervasive - Large (31-100%) Moderate - Slight (1-30%) High (Continuing) Wild Turkeys (recently re-introduced) have caused damage to the forest floor in nearby areas, but to date there is no evidence of direct impacts to Spotted Wintergreen. Turkeys are considered as a threat here as their populations have increased as a result of human activities. At Spooky Hollow, some plants disappeared overnight and deer-browsing was the reason; exclosures have been successful - cameras have recorded presence of turkey and deer (unknown impacts). Exclosure at Spooky Hollow has allowed site to recover from deer browsing.
8.3 Introduced genetic material blank blank blank blank blank blank
9 Pollution blank Negligible Negligible (<1%) Extreme - Serious (31-100%) High (Continuing) blank
9.1 Household sewage & urban waste water blank blank blank blank blank blank
9.2 Industrial & military effluents blank blank blank blank blank blank
9.3 Agricultural & forestry effluents blank blank blank blank blank blank
9.4 Garbage & solid waste blank Negligible Negligible (<1%) Extreme - Serious (31-100%) High (Continuing) Garbage dumping has happened at least at one site; roadside dumping occurs frequently & one roadside population is vulnerable.
9.5 Air-borne pollutants blank blank blank blank blank Pollution (increased nitrogen levels) can impact associated mycorrhizal fungi, but unknown whether there is an impact. Highly speculative & little evidence at this point, so not included as a threat. Unknown whether 2013 closing of Nanticoke Generating Station is of potential negative or positive impact.
9.6 Excess energy blank blank blank blank blank blank
10 Geological events blank blank blank blank blank blank
10.1 Volcanoes blank blank blank blank blank blank
10.2 Earthquakes/tsunamis blank blank blank blank blank blank
10.3 Avalanches/landslides blank blank blank blank blank blank
11 Climate change & severe weather blank Not Calculated (outside assessment timeframe) Pervasive (71-100%) Unknown Low (Possibly in the long term, >10 yrs) Potential impact but unknown as species occurs in a wide climatic range.
11.1 Habitat shifting & alteration blank blank blank blank blank blank
11.2 Droughts blank blank blank blank blank blank
11.3 Temperature extremes blank blank blank blank blank blank
11.4 Storms & flooding blank blank blank blank blank blank

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