Geothallus tuberosus
CR

Geothallus tuberosus

Stable

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

Overview

Geothallus is a monotypic genus of liverwort in the family Sphaerocarpaceae. Its sole species, Geothallus tuberosus, is a critically endangered species endemic to California in the United States. Described in 1896 by American botanist Douglas Houghton Campbell, it is commonly known as Campbell's liverwort.

Geothallus tuberosus faces severe threats from habitat destruction due to urban development and agricultural expansion across its limited range. The species' specialized soil crust habitat requirements make it particularly vulnerable to ground disturbance and trampling by livestock. Climate change poses an additional threat through altered precipitation patterns that could disrupt the delicate moisture balance required for this cryptobiotic soil organism.

Threat summary

Habitat

Geothallus tuberosus inhabits specialized cryptobiotic soil crusts in arid and semi-arid environments, typically found in undisturbed desert soils with specific moisture and mineral requirements. This lichen forms part of the biological soil crust community that stabilizes desert soils and provides essential ecosystem functions in fragile dryland ecosystems.

Marine coastal/supratidal· majorShrubland· majorWetlands (inland)· major

Conservation measures underway

Site/area protection

Other threatened species in SPHAEROCARPACEAE

EN

Sphaerocarpos drewiae

Unknown

Threatened in United States

VU

Lepiota echinella

Unknown
VU

Paddlefish

Polyodon spathula

Unknown
VU

Copper Shark

Carcharhinus brachyurus

Declining
EN

Lyophyllum deliberatum

Unknown

Frequently asked questions

Why is Geothallus tuberosus classified as Critically Endangered?
Geothallus tuberosus 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. Geothallus tuberosus faces severe threats from habitat destruction due to urban development and agricultural expansion across its limited range. The species' specialized soil crust habitat requirements make it particularly vulnerable to ground disturbance and trampling by livestock. Climate change poses an additional threat through altered precipitation patterns that could disrupt the delicate moisture balance required for this cryptobiotic soil organism.
Where does Geothallus tuberosus live?
Geothallus tuberosus occurs in United States. Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Geothallus tuberosus?
The main threats to Geothallus tuberosus are 1.1, 5.3, 7.3, and ai-1. The full IUCN-classified threat record for this species is detailed on the species page.

Get weekly conservation intelligence

One short digest a week of the most striking species and country data we ship, plus breaking conservation news paired with our database where it matters.

Free, no spam. One-click unsubscribe in every email.