Taxon Report

Cladonia firma (Nyl.) Nyl.

popcorn lichen

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Taxon Summary

Cladonia firma, commonly known as popcorn lichen, is a squamulose lichen (terricolous) in the Cladoniaceae that is . It occurs within Coastal dunes (stabilized), and Coastal scrub, growing at elevations from 30 to 75 meters. Cladonia firma is ranked 2B.1, Plants Rare, Threatened, or Endangered in California, But More Common Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Cladonia firma (Nyl.) Nyl.
Common Name:	popcorn lichen
Family:	Cladoniaceae
Element Code:	NLT0008460
USDA Plants Symbol:	CLFI4
Synonyms/Other Names:

Ecology and Life History


Lifeform:	squamulose lichen (terricolous)
Blooming Period:
Elevation:	30-75 (100-245)
General Habitats:	Coastal dunes, Coastal scrub
Microhabitat:
Microhabitat Details:	On soil, detritus, and/or moss

Conservation Status


CA Rare Plant Rank:	2B.1
Global Rank:	G4
State Rank:	S1
State List:	None
Fed List:	None
Other Status:
CRPR Changes:	added to 2B.1 on 2014-03-01

Occurrence Data from the CNDDB


Total Occurrences:	4
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	4

Location


California Endemic: False
California Counties and Islands: Name (Code)
San Luis Obispo (SLO)
Quads: Name (Quad Code)
Morro Bay South (3512037)

Threat List Data from the CNDDB


Threat List Total:	2
EOs with Threat Listed:	Total EOs	% of EOs
	1	25 %
Non-native plant impacts	1	25%
Other	1	25%

Notes



Known in CA only from Morro Bay and Baywood-Los Osos areas. Threatened by habitat loss, recreational activities, and non-native plants. Often forms biological soil crusts with other lichens and mosses. See Bulletin of the California Lichen Society 14(2):40-44 (2007) for CALS Conservation Committee sponsorship.
Threats:

Taxonomy:

Selected References

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 2 April 2025].