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Bacidia schweinitzii (Fr. ex Tuck.) A. Schneid.

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Scientific name
Bacidia schweinitzii
(Fr. ex Tuck.) A. Schneid.
Common names
Surprise Lichen
Champion Crust
IUCN Specialist Group
Assessment status
Assessment date
IUCN Red List Category
Lendemer, J.
Allen, J.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/180096939/219189896


Bacidia schweinitzii is a crustose lichen that is widespread in eastern North America with scattered disjunct occurrences in eastern Asia. It is not under any significant threat of extinction at the moment and is assessed as Least Concern.

Taxonomic notes

Bacidia schweintizii was described over a century ago and has been treated taxonomically in multiple detailed treatments (e.g. Ekman 1996, Lendemer et al. 2016). It is a highly distinctive crustose lichen that can easily be recognized in the field and laboratory.

Geographic range

The species occurs throughout eastern North America and is widely distributed from southern Canada to central Florida in the United States. Scattered occurrences have also been reported from eastern Asia.

Population and Trends

Comprehensive detailed population data are unavailable for Bacidia schweinitzii. The status of the population is suspected to be stable given that it is common and widespread in many habitats and there is no indication the species is restricted to a narrow range of habitats or substrates (Ekman 1996, Lendemer et al. 2016).

Population Trend: stable

Habitat and Ecology

Bacidia schweinitzii primarily occurs on the bases and boles of trees, especially in humid habitats. It is most often found on the bark of hardwood trees, but frequently also occurs on the bark of certain conifers such as cypress (Taxodium). It is widely distributed in temperate and subtropical areas of eastern North America as with disjunct occurrences in eastern Asia.


Threats to Bacidia schweinitzii are primarily habitat loss, air pollution and urbanization as it does not typically occur in urban areas.

Conservation Actions

Bacidia schweinitzii would benefit from broader awareness and training as to the impacts of broad scale habitat loss and pollution on lichens. This species would moreover benefit from demographic studies and long-term monitoring of population trends. Many sites where this species occurs are located on public lands and in protected areas where it is incidentally protected.

Source and Citation

Lendemer, J. 2022. Bacidia schweinitzii. The IUCN Red List of Threatened Species 2022: e.T180096939A219189896. https://dx.doi.org/10.2305/IUCN.UK.2022-1.RLTS.T180096939A219189896.en .Accessed on 10 December 2023

Country occurrence