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Common Antler Lichen (Pseudevernia consocians)

Life history

Species overview

Common Antler Lichen (Pseudevernia consocians), a Wisconsin Special Concern lichen, is found on bark in wet northern forests such as black spruce or white cedar swamps



  • Distinguishing characteristics: Common antler lichen can be distinguished from look-alikes by the lack of cup-shaped fruiting bodies (apothecia) and abundant but minute thallus outgrowths (isidia), which give the lichen a fuzzy or ragged appearance.
  • Fruiting body characteristics: Apothecia (cup- or disc-shaped fruiting structures) usually absent.
  • Thallus (vegetative body) characteristics: Thallus light gray above to darker gray or black below; lobes linear, 1-1.5mm wide and with forked branching.


  • Growth form: Foliose or fruticose lichen
  • Vegetative reproduction: Isidia (vegetative propagules extending from the center of the thallus surface and margins) numerous, cylindrical and sometimes branched.
  • Comments: Associated species: Black spruce, tamarack, white cedar and ericads. Outside of Wisconsin it has been found on pine bark.

General overview of lichen morphology

Lichens represent a unique symbiotic relationship between two or sometimes three organisms: a fungus; an alga; and/or a cyanobacterium. This figure provides a good overview of a generalized lichen. The main body of the lichen is called the thallus. The thallus is the vegetative part of the lichen (i.e., not including any reproductive structures like apothecia) and is often what we visually associate with a lichen. The figure above depicts a foliose thallus with the upper surface curled up in places to reveal the lower thallus surface. The magnified thallus cross section on the right shows a number of additional layers. In this example, the top layer is the upper cortex, which is made up of fungal filaments. Underneath that is the photobiont, either an alga or a cyanobacterium or both. Beneath the photobiont is a loose layer of fungal strands (hyphae) called the medulla, and below the medulla is the lower cortex.

Lichens can reproduce sexually via spores, which are associated with the fungal component of the lichen. However, these spores must again find an appropriate photobiont before a new lichen is formed. Lichens can also reproduce asexually. The two structures shown in the box on the left function in asexual reproduction. Both isidia and soredia are essentially photobionts wrapped in a fungal skin. These can be released from the thallus to form new lichens.

Please see the glossary below for descriptions of more lichen-related terms and photos that depict these features.

Glossary of common lichen terms [PDF]

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - state and federal - and the rank (S and G Ranks) for Common Antler Lichen (Pseudevernia consocians). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Documented locations of Pseudevernia consocians in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusSC
Federal Status in Wisconsinnone
State RankS1
Global RankG4G5
Mapped in NHIY

Habitats and landscapes

The Natural Heritage Inventory has developed scores indicating the degree to which certain rare lichen species are associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

General habitat information

Found on bark in wet northern forests such as black spruce or white cedar swamps

Natural communities

This table lists the natural communities that are associated with Common Antler Lichen. Scores for natural community associations are: "significant" association (score=3), "moderate association" (score=2) or the species can be present but is only weakly associated with the community (score=1).

Natural communities score
Black Spruce Swamp 3
Poor Fen 2
Muskeg 3
Open Bog 3

Ecological landscapes

This table lists the ecological landscape association scores for Common Antler Lichen. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Ecological landscape score
Northern Highland 3
Superior Coastal Plain 3

Species guidance

The Endangered Resources Program has developed avoidance measures and management guidelines for lichens on the Natural Heritage Working List. These are a work in progress, and we welcome your suggestions and feedback.

Avoidance measures

These are specific actions designed to avoid "take" (mortality) of this species.

  • No avoidance measures have been developed for this species.

Management guidance

Management guidelines are additional considerations that may help maintain or enhance habitat for this species

  • Minimize disturbance to hydrology, including soil disturbance from rutting.
  • Avoid rapid and dramatic reductions in canopy cover or basal area in wet areas to reduce risk of swamping.
  • Species is extremely rare in the state and is of the highest priority for conservation; please consult with your District Ecologist or NHI staff to determine if the species is present on your site and for specific recommendations.


Common Antler Lichen  Photo.

Iaisi, the abundant outgrowths on the thallus surface, can detach easily, becoming vegetative propagules, give this species a fuzzy appearance.

Photo © Samuel Brinker.

Common Antler Lichen  Photo.

Common antler lichen is tufted like a fruticose lichen but has flat branches with mostly distinct upper and lower surfaces like a foliose lichen.

Photo © Samuel Brinker.

Common Antler Lichen  Photo.

The thallus outgrowths (isidia) can be on the thallus surface or margins as is mostly the case in this photo.

Photo © Troy McMullin.

Support for Wisconsin's rare lichen information has been provided by the Wisconsin Rare Plant Preservation Fund. To donate, visit the Natural Resources Foundation of Wisconsin [exit DNR].

Last revised: Thursday, October 08, 2020
Southwest Savanna Southern Lake Michigan Coastal Western Coulees and Ridges Southeast Glacial Plains Central Sand Hills Central Lake Michigan Coastal Central Sand Plains Northern Lake Michigan Coastal Northern Lake Michigan Coastal Northeast Sands Western Prairie North Central Forest Northern Highlands Northwest Lowlands Northwest Sands Northwest Lowlands Superior Coastal Plains Forest Transition