Pale-bellied Frost Lichen
Scientific Name: Physconia subpallida
Taxonomy Group: Lichens
COSEWIC Range: Ontario, Quebec
COSEWIC Assessment Date and Status Change: November 2009
COSEWIC Status: Endangered
COSEWIC Status Criteria: B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v); C2a(i); D1
COSEWIC Reason for Designation: This lichen is an eastern North American endemic that, in Canada, is restricted to 2 known locations in southern Ontario. The lichen grows as an epiphyte on hardwoods and requires bark with high pH and high moisture holding capacity. Only 45 individuals are known, growing on 16 trees. The lichen appears to have suffered a dramatic population decline throughout its range since the early 1900’s; in Canada 4 historical sites have been lost. The major threat to the lichen is air pollution and timber harvest.
COSEWIC History of Status Designation: Designated Endangered in November 2009.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2012-06-20
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
Physconia subpallida is a rosette forming foliose lichen that can be strikingly white in the field. There are several distinctive characters that separate it from other eastern North American Physconia lichens including: 1) absence of common means of asexual production in lichens (isidia and soredia), 2) presence of fruiting bodies (apothecia) and/or lobules, and 3) a pale undersurface with spreading attachment structures (rhizines) in distinct clusters. Physconia subpallida is an eastern North American endemic. It is the only eastern North American member of the genus that is commonly fertile, has lobules, and has a pale undersurface. These unique characters increase the importance of this species to understanding the genus as a whole. Two distinct forms of this lichen are known. One form is commonly fertile with flattened appressed lobules and the other form is generally sterile with cylindrical erect lobules. This presents a opportunity to investigate the development of apothecia and study the expression of the same morphological structures in a single fungal genome. As a lichen that appears to be extremely sensitive to air pollution, Physconia subpallida may be a valuable indicator of forest health and air quality in southern Ontario. (Updated 2017/06/13)
Distribution and Population
Physconia subpallida is an eastern North American endemic occurring only in the United States and Canada. It is known, at least historically, from Massachusetts and New Hampshire west to southern Ontario, Michigan, and eastern Iowa south to central Illinois, Ohio, and Virginia. It is also disjunct in the Ozarks region of eastern Oklahoma and northwestern Arkansas. In Canada, P. subpallida is restricted to southern Ontario where it is at the northern edge of its range. There are only two known locations. (Updated 2017/06/13)
This lichen mainly grows as an epiphyte on hardwood trees, but has also been collected from fence rails and rocks, including limestone. The host trees P. subpallida is known to occur on include: Fraxinus sp. (Ash), Juglans nigra(Black Walnut), Ostrya virginiana(Hop–hornbeam), and Ulmus sp. (Elm; including Ulmus americana). At the two known extant sites in Canada the lichen is restricted to Ostrya virginiana. The lichen seems to require a substratum with relatively high pH and moisture holding capacity. (Updated 2017/06/13)
Physconia subpallida can reproduce via sexually and asexually produced spores. It may also be able to reproduce asexually via dispersal of lobules. However, the lichen lacks common means of asexual production in lichens (isidia and soredia), and it is possible that the larger lobules are not as easily dispersed as these more common, smaller propagules. (Updated 2017/06/13)
Habitat availability for this lichen in southern Ontario has been negatively affected, over the past century, primarily by air pollution as well as by changes in land use and forest composition. The two extant Canadian populations are both currently unprotected on provincial lands that are open to logging operations. Improvements in air quality have significantly decreased sulfate deposition and so this rare lichen may be able to expand its populations in the long–term. (Updated 2017/06/13)
The Pale-bellied Frost Lichen is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Pale-bellied Frost Lichen (Physconia subpallida) in Canada
Status Final posting on SAR registry
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
11 record(s) found.
- Reports on the Progress of Recovery Document Implementation (1 record(s) found.)
- COSEWIC Status Reports (1 record(s) found.)
- COSEWIC Assessments (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Action Plans (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Recovery Document Posting Plans (1 record(s) found.)
Reports on the Progress of Recovery Document Implementation
COSEWIC Status Reports
Response Statement - Pale-bellied Frost Lichen (2010-12-02)This lichen is an eastern North American endemic that, in Canada, is restricted to 2 known locations in southern Ontario. The lichen grows as an epiphyte on hardwoods and requires bark with high pH and high moisture holding capacity. Only 45 individuals are known, growing on 16 trees. The lichen appears to have suffered a dramatic population decline throughout its range since the early 1900’s; in Canada 4 historical sites have been lost. The major threat to the lichen is air pollution and timber harvest.
COSEWIC Annual Reports
COSEWIC Annual Report - 2010 (2010-09-03)Under Canada’s Species At Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. During the past year, COSEWIC held two Wildlife Species Assessment Meetings and reviewed the status of 79 wildlife species (species, subspecies, populations). During the meeting of November 2009, COSEWIC assessed or reviewed the classification of the status of 28 wildlife species. COSEWIC assessed or reviewed the classification of an additional 51 wildlife species (species, subspecies and populations) during their April 2010 meeting. For species already found on Schedule 1 of SARA, the classification of 32 species was reviewed by COSEWIC and the status of the wildlife species was confirmed to be in the same category (extirpated - no longer found in the wild in Canada but occurring elsewhere, endangered, threatened or of special concern). The wildlife species assessment results for the 2009-2010 reporting period include the following: Extirpated: 6 Endangered: 39 Threatened: 16 Special Concern: 17 Data Deficient: 1 This report transmits to the Minister the status of 46 species newly classified as extirpated, endangered, threatened or of special concern, fulfilling COSEWIC’s obligations under SARA Section 24 and 25. A full detailed summary of the assessment for each species and the reason for the designation can be found in Appendix I of the attached report. Since its inception, COSEWIC has assessed 602 wildlife species in various risk categories, including 262 Endangered, 151 Threatened, 166 Special Concern and 23 Extirpated. In addition, 13 wildlife species have been assessed as Extinct. Also, to date, 46 wildlife species have been identified by COSEWIC as Data Deficient and 166 wildlife species were assessed as Not at Risk. This year has been a particularly productive year for COSEWIC’s Aboriginal Traditional Knowledge (ATK) Subcommittee. In April 2010 COSEWIC approved the Aboriginal Traditional Knowledge Process and Protocol Guidelines, providing clear and agreed principles for the gathering of Aboriginal Traditional Knowledge to carry out COSEWIC functions as required under Section 15(2) of SARA (See Appendix III of the attached report). We are grateful for the rich and enthusiastic contribution made by community elders and experts in helping the ATK Subcommittee prepare the ATK protocols.