Species Profile

Cryptic Paw Lichen

Scientific Name: Nephroma occultum
Other/Previous Names: Cryptic Paw
Taxonomy Group: Lichens
Range: British Columbia
Last COSEWIC Assessment: April 2006
Last COSEWIC Designation: Special Concern
SARA Status: Schedule 1, Special Concern

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Quick Links: | Photo | Description | Habitat | Biology | Threats | Protection | Recovery Team | National Recovery Program | Documents

Image of Cryptic Paw Lichen

Cryptic Paw Lichen Photo 1



The lichen is leafy, rounded and loosely pressed in appearance. It measures 3 to 7 cm across. The upper surface is pale yellowish- to greenish- or bluish-grey, while the lower surface is pale tan at the edges, blackish toward the centre. Both sides are dull and naked. The bottom is finely wrinkled. A lichen is a plant organism composed of a fungus and an alga in symbiotic association.


Distribution and Population

The Cryptic Paw Lichen is found only in the Pacific Northwest of North America. There are 28 locations in which the lichen is known to occur (21 in British Columbia, five in Oregon, two in Washington). The density of these lichens ranges from distinctly sparse to locally frequent (20 thalli (plant-bodies) per square metre considered frequent). Only one or two thalli per site were recently found in more than half the B.C. sites, but virtually all the plants were vigourous.



The Cryptic Paw Lichen is restricted to humid old-growth forests at lower elevations in mountainous regions. It appears to have very specific ecological requirements, which include high humidity and moderate summer temperatures.



The species reproduces through spores (reproductive cells). Spores grow to become individuals identical to the parents, in a suitable habitat. Splashing rain carries spores short distances. Migrating birds and other animals disperse spores over longer distances.



Continued logging of B.C.'s old-growth forests is causing the species' steady, seemingly permanent, decline. Once the plant has disappeared from a site, it is not likely to reoccur in secondary-growth replacement forests. The species' limited distribution results mostly from its specific climatic requirements. Natural causes of mortality are competition from other lichens and forest defoliation by insects.



Federal Protection

More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.


Recovery Team

Team for the Cryptic Paw Lichen

  • Brenda Costanzo - Chair/Contact - Government of BC
    Phone: 250-387-9611  Fax: 250-356-9145  Send Email



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.

9 record(s) found.

COSEWIC Status Reports

  • COSEWIC assessment and update status report on the cryptic paw Nephroma occultum in Canada (2006)

    Nephroma occultum is a rare lichen, endemic to Western North America. It is strongly associated with humid old growth forests and is characterized by a yellowish, greenish, or bluish-grey upper surface with net-shaped ridges, and a hairless tan to sometimes blackish lower surface. It is commonly is 2-7 cm broad and has rounded lobes 4-12 mm wide. It produces many asexual propagules, called soredia, along the margins and the ridges of the upper surface, and lacks apothecia, the spore-producing sexual stage of reproduction.

COSEWIC Assessments

Response Statements

  • Response Statements - Cryptic Paw (2006)

    This foliose lichen is endemic to western North America where it is known in Canada from 45 locations, however there are likely more undiscovered locations. The Canadian sites account for more than 50% of the global range with only 5 locations protected from forest harvesting. The species has restricted habitat requirements and grows in mid to lower canopy of old growth coastal and interior humid cedar-hemlock forest. It reproduces only by vegetative propagules with limited dispersal distance. The species is vulnerable to forest harvesting, changes in understory humidity, insect defoliation (hemlock looper), and fire.

Management Plans

  • Management Plan for the Cryptic Paw Lichen (Nephroma occultum) in Canada (2012)

    The Cryptic Paw Lichen (Nephroma occultum) was listed as Special Concern on the federal Species at Risk Act (SARA) Schedule 1 in 2007. In British Columbia, Cryptic Paw is ranked S2S3 (imperiled to special concern, vulnerable to extirpation or extinction) by the Conservation Data Centre. SARA section 65 requires the competent Minister, which in this case, is the federal Minister of the Environment to prepare a management plan for all listed species of special concern. SARA section 69 allows the Minister to adopt all or part of an existing plan for the species if the Minister is of the opinion that an existing plan relating to wildlife species includes adequate measures for the conservation of the species. This management plan has been prepared by B.C. Ministry of Environment as advice to the responsible jurisdictions and organizations that may be involved in managing the species. Environment Canada has prepared a federal addition to meet the requirements of SARA.


  • Order Acknowledging Receipt of the Assessments Done Pursuant to Subsection 23(1) of the Act (2007) (2007)

    This Order acknowledges receipt by the Governor in Council of the assessments of the status of 40 species done pursuant to paragraph 15(1)(a) and in accordance with subsection 23(1) of the Species at Risk Act (SARA) by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The purpose of SARA is to prevent wildlife species from being extirpated or becoming extinct, to provide for the recovery of wildlife species that are extirpated, endangered or threatened as a result of human activity and to manage species of special concern to prevent them from becoming endangered or threatened.
  • Order Amending Schedule 1 to the Species at Risk Act (2007)

    Her Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, pursuant to section 27 of the Species at Risk Act, hereby makes the annexed Order Amending Schedules 1 to 3 to the Species at Risk Act.
  • Order Amending Schedule 1 to the Species at Risk Act (2012)

    The purpose of the Order Amending Schedule 1 to the Species at Risk Act is to add 18 species to Schedule 1, the List of Wildlife Species at Risk (the List), and to reclassify 7 listed species, pursuant to subsection 27(1) of SARA. This amendment is made on the recommendation of the Minister of the Environment based on scientific assessments by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and on consultations with governments, Aboriginal peoples, stakeholders and the Canadian public.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2006 (2006)

    2006 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.

Consultation Documents

  • Consultation on Amending the List of Species under the Species at Risk Act Terrestrial Species: December 2006 (2006)

    The Government of Canada proclaimed the Species at Risk Act (SARA) on June 5, 2003 as part of its strategy for the protection of wildlife species at risk. Attached to the Act is Schedule 1, the list of the species that receive protection under SARA, hereinafter referred to as the 'SARA list'. Canadians are invited to comment on whether all or some of the species included in this document should be added to the SARA list. Please submit your comments by March 16, 2007 for species undergoing normal consultations and by March 14, 2008 for species undergoing extended consultations.