Flaking Tarpaper Lichen
CR

Flaking Tarpaper Lichen

Collema flaccidum

Unknown

Photo: Wikimedia Commons (CC) via https://en.wikipedia.org/wiki/Collema_flaccidum

Overview

Flaking Tarpaper Lichen (Collema flaccidum) is a gelatinous, dark-colored lichen that forms thin, flaky crusts resembling weathered tar paper on its substrate. This cyanobacterial lichen plays a crucial role in nitrogen fixation and serves as a pioneer species in ecosystem succession, contributing to soil formation and providing microhabitat for invertebrates.

Flaking Tarpaper Lichen (Collema flaccidum) is critically endangered primarily due to habitat loss and degradation from urban development, agricultural expansion, and infrastructure projects that destroy the specific rock substrates it requires. Air pollution, particularly nitrogen deposition and acid rain, severely impacts this sensitive lichen species by altering its chemical environment and disrupting symbiotic relationships.

Threat summary

Habitat

Collema flaccidum typically grows on calcareous rocks, old mortar, and concrete structures in areas with high humidity and intermittent moisture. It favors sheltered locations such as north-facing walls, cave entrances, and shaded rock crevices where it can access periodic water while avoiding direct sunlight.

TERRESTRIAL· major

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Scytinium gelatinosum

Unknown
Jelly LichenCR

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Leptogium cochleatum

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Scytinium fragrans

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Frequently asked questions

Why is Flaking Tarpaper Lichen classified as Critically Endangered?
Flaking Tarpaper Lichen is classified as Critically Endangered — facing an extremely high risk of extinction in the wild — because population sizes are very small, declining sharply, or restricted to a tiny range. Flaking Tarpaper Lichen (Collema flaccidum) is critically endangered primarily due to habitat loss and degradation from urban development, agricultural expansion, and infrastructure projects that destroy the specific rock substrates it requires. Air pollution, particularly nitrogen deposition and acid rain, severely impacts this sensitive lichen species by altering its chemical environment and disrupting symbiotic relationships.
Where does Flaking Tarpaper Lichen live?
Flaking Tarpaper Lichen occurs in across multiple regions. Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Flaking Tarpaper Lichen?
The main threats to Flaking Tarpaper Lichen are ai-1, ai-2, ai-3, and ai-4. The full IUCN-classified threat record for this species is detailed on the species page.

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