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Treeflute (Menegazzia terebrata)

Life history

Species overview

Treeflute (Menegazzia terebrata), a Wisconsin Special Concern lichen, is found on bark in Northern Wet-mesic Forests, often on white cedar

Synonyms: Hypogymnia pertusa


  • Distinguishing characteristics: The holes on the upper surface of the thallus make treeflute very distinctive. Similar lichens are Hypogymnia species, which also have a tube-like thallus, but if there are any perforations, they are on the lobe tips or axils. Cavernularia lichens have perforations on the underside of the thallus and are generally smaller.
  • Fruiting body characteristics: Apothecia (cup- or disc-shaped fruiting structures) usually absent.
  • Thallus (vegetative body) characteristics: Thallus light blue-green-gray with 1-2mm wide rounded lobes, inflated and tube-like, and with distinctive large, round perforations in the upper surface; lower surface black, wrinkled, without root-like attachments anchoring thallus to substrate (rhizines).


  • Growth form: Foliose lichen
  • Vegetative reproduction: Vegetative propagules called soredia occur in powdery masses toward the center of the upper thallus.
  • Comments: Outside of Wisconsin, treeflute is known to grow on birch, alder and beech.

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 Treeflute (Menegazzia terebrata). 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 Menegazzia terebrata in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusSC
Federal Status in Wisconsinnone
State RankS1
Global RankG5
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 Northern Wet-mesic Forests, often on white cedar

Natural communities

This table lists the natural communities that are associated with Treeflute. 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
Northern Wet-mesic Forest 3

Ecological landscapes

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

Ecological landscape score
Forest Transition 2
North Central Forest 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.

  • Avoid known individual plant locations and conduct operations elsewhere when they are least likely to cause damage. Ideally, this would involve frozen, snow-covered ground. However, in areas of the state where frozen conditions are unreliable, very dry soils late in the growing season might be the best available alternative. Consult with a biologist, if needed.

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.
  • Maintain high forest canopy cover; this species requires shaded habitat conditions.
  • 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.


Treeflute  Photo.

The black dots on the upper surface of the thallus are perforations, which are a key diagnostic feature of this lichen.

Photo © Einar Timdal.

Treeflute  Photo.

Photo © Einar Timdal.

Treeflute  Photo.

Photo © Hans Schwencke.

Treeflute  Photo.

The upper thallus surface can have range from green- to blue-grey.

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