Yellow Map Lichen

Rhizocarpon geographicum (L.) DC.

Also called: map lichen, world map lichen

Edibility

Edibility unknown — do not eat

Never eat a wild mushroom based on this site or any app.

Photos

Photo: Arvel Hernandez. CC-BY. Source (inaturalist)
Photo: Caleb Catto. CC-BY. Source (inaturalist)
Photo: Annie Evankow. CC-BY. Source (inaturalist)
Photo: John Brew. CC-BY. Source (inaturalist)

Lookalikes

No lookalikes are recorded for this species yet. That does not mean there are none. Many mushrooms look alike, so never rely on appearance alone.

Season

When this species has been recorded, by month, from open-licensed US and Canada observations. It shows when people report it, not a guarantee it is fruiting.

The highlighted bar is the current month.

View season data as a table

Recorded observations of Yellow Map Lichen by month
Month	Records
January	10
February	7
March	21
April	38
May	76
June	277
July	781
August	674
September	232
October	85
November	21
December	5

Where it is found

States and provinces with the most records. Check the foraging rules for the place you plan to visit.

Nunavut 211 records · Foraging rules
Washington 176 records · Foraging rules
Colorado 172 records · Foraging rules
British Columbia 171 records · Foraging rules
California 149 records · Foraging rules
Alaska 140 records · Foraging rules
Quebec 124 records · Foraging rules
Montana 98 records · Foraging rules
New Hampshire 98 records · Foraging rules
Northwest Territories 93 records · Foraging rules
Ontario 93 records · Foraging rules
Wyoming 71 records · Foraging rules
Yukon 71 records · Foraging rules
Newfoundland and Labrador 68 records · Foraging rules
Maine 66 records · Foraging rules

Show 24 more

Michigan64 records
Minnesota63 records
Alberta56 records
Oregon48 records
Manitoba39 records
Arizona37 records
Vermont35 records
Utah33 records
Idaho27 records
South Dakota25 records
New York23 records
North Carolina21 records
New Mexico21 records
Nova Scotia13 records
North Dakota11 records
Virginia10 records
Tennessee8 records
Hawaii7 records
New Brunswick5 records
Nevada3 records
West Virginia2 records
Missouri1 records
Maryland1 records
Oklahoma1 records

All state and province foraging laws

About

Rhizocarpon geographicum (the map lichen or yellow map lichen) is a species of lichen, which grows on rocks in mountainous areas of low air pollution. Each lichen is a flat patch bordered by a black line of fungal hyphae. These patches grow adjacent to each other, leading to the appearance of a map or a patchwork field. When circular, or roughly circular, the diameter of this lichen species has been widely used to help determining the relative age of deposits, e.g. moraine systems, thus revealing evidence of glacial advances. The process is termed lichenometry.

From Wikipedia, CC BY-SA 4.0. Read the original article.

More in the genus Rhizocarpon

Never eat a wild mushroom based on this site or any app. See safety basics and the disclaimer.