Fauna
Fungus

Rock Greenshield Lichen

Flavoparmelia baltimorensis

Also known as Baltimore Greenshield Lichen

Rock greenshield lichens spread across non-calcareous boulders and shaded rock faces, forming broad, pale yellow-green rosettes that cling tightly to the stone. Their upper surface is characterized by distinctive pustule-like outgrowths that fragment easily, dispersing symbiotic algal cells and fungal hyphae together to establish new colonies. Highly enduring yet slow-growing, individual colonies can persist on stable stone surfaces for many decades while slowly weathering the minerals beneath them.

LichenSaxicolousSymbiotic
Rock Greenshield Lichen reference1 / 7
(c) Jon P. Ruddy, some rights reserved (CC BY), uploaded by Jon P. Ruddy · cc-by
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Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & preyPhototrophic symbiosis via chlorophyte green algae
Predators
  • Oribatid mites
  • Springtails
  • Slugs
ThreatsSulfur dioxide air pollution, acid precipitation, and boulder disturbance
HabitatsSiliceous rock outcrops, granite boulders, sandstone cliffs, and headstones
Life spanDecades to centuries
Classification
  1. OrderLecanorales
  2. FamilyParmeliaceae
  3. GenusFlavoparmelia
  4. SpeciesFlavoparmelia baltimorensis
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Harmless to observe; many wild fungi have toxic look-alikes, so never ingest wild specimens.
Responsible observation
  • Hand Lens Inspection: Use a 10x magnifier to inspect the granular pustules on the upper lobes.
  • Rock Conservation: Avoid scraping thalli from boulders, as lichens take decades to recolonize bare stone.
  • Air Quality Monitoring: Treat abundant growth as a helpful sign of low local sulfur dioxide levels.
Related species
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