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Federal Protection: No US federal protection

State Protection: No Georgia state protection

Global Rank: GNR

State Rank: SNR

Element Locations Tracked in Biotics: No

SWAP 2015 Species of Greatest Conservation Need (SGCN): No

SWAP 2025 Species of Greatest Conservation Need (SGCN): No

2025 SGCN Priority Tier:

Element Occurrences (EOs) in Georgia: 0

Habitat Summary for element in Georgia: Mesic hardwood forests, swamp forests

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Description

Thallus inconspicuous, black lirellae short, sessile, with exposed black disk; MICROSCOPY: spores colorless, 6-celled, about 18-20 x 5-6 µm; FIELD ID: cannot be told from Arthonia atra in field, even with experience; needs dissection to observe spores

Similar Species

Of the Opegrapha group on bark with short black lirellae, Arthonia atra also has exposed disks, but it has 4-celled spores; of the species with longer, closed lirellae, Opegrapha vulgata also has 6-celled spores, but they are narrow: 3-4 µm wide; O. candida has 4-celled spores with puffy, smooth lirellae; & Zwackhia viridis has 12-14-celled banana-shaped spores; there is also a probably-undescribed Opegrapha with spores identical to Zwackhia & lirellae identical to the present species

Related Rare Species

None

Habitat

Mesic hardwood forests, swamp forests; hardwood bark: 35% Quercus, 21% Acer, 15% Carya & 27% other hardwoods or unknowns; 1 record on Taxodium

Life History

Corticolous crustose lichenized fungus; photobiont an alga in genus Trentepohlia

Survey Recommendations

None

Range

Found across the state, although rarely in the Southern Blue Ridge

Threats

Unknown

Georgia Conservation Status

Uncommon

Conservation Management Recommendations

None

References

Brodo, I. M. 2001. Lichens of North America. Yale University Press, New Haven, Conn.

Brodo, I. M. 2016. Keys to lichens of North America: revised and expanded. Yale University Press, New Haven, Conn.

Esslinger, T. L. 2021. A cumulative checklist for the lichen-forming, lichenicolous and allied fungi of the continental United States and Canada. Version 24. Opuscula Philolichenum 20: 100-394.

Harris, R. C. 1995. More Florida lichens including the 10-cent tour of the pyrenolichens. Unpublished manuscript, Bronx, N.Y.

Authors of Account

Malcolm Hodges

Date Compiled or Updated

27 February 2022