Star Rosette Lichen

Conservation Status

IUCN Red List

not listed

NatureServe

NNR - Unranked

Minnesota

not listed

Description

Star Rosette Lichen is widespread and common across the United States. It is very common in Minnesota, and has been recorded in 75 of the state’s 87 counties. It grows on the bark of elm and poplar trees and alder shrubs.

The vegetative body (thallus) is leaf-like (foliose), up to 1½″ in diameter, and divided into lobes. It sometimes merges with adjacent thalli, creating what appears to be one large thallus. It is attached to the substrate (bark) by pale anchoring structures (rhizines). The lobes are truncate at the tip can be 1 ⁄64″ to 1 ⁄16″ (0.5 to 1.5 mm) wide, but are usually no more than 1 ⁄64″ (0.5 mm) wide. The upperside is whitish-gray to cream-colored, usually darker in the center and paler at the margins. The surface has neither powdery dull granules (soredia) nor shiny granules (isidia). The underside is white to brownish.

Disk-like, spore-producing structures (apothecia) are usually abundant. The disks are 1 ⁄64″to ⅛″ in diameter, dark brown, and shaped like a plate. Each disk has a thick ring of tissue around it that resembles the tissue of the vegetative (non-fruiting) part of the lichen. The disks turn gray when dry.

Similar Species

Ecology

Substrate

Trees

Growth Form

Foliose

Habitat

Hosts

Elm, poplar, and alder

Distribution

Sources

7, 24, 30, 77, 83.

Biodiversity occurrence data published by: Minnesota Biodiversity Atlas (accessed through the Minnesota Biodiversity Atlas Portal, bellatlas.umn.edu. Accessed 4/30/2024).

The Consortium of North American Lichen Herbaria (CNALH) https://lichenportal.org/cnalh/index.php. Accessed 4/30/2024.

Mycology Collections Portal (MyCoPortal) https://www.mycoportal.org/portal/collections/index.php). Accessed 4/30/2024.

Physcia stellaris (L.) Nyl. in GBIF Secretariat (2023). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org. Accessed 4/30/2024.

Fink, B. (1910). The Lichens of Minnesota. United States: U.S. Government Printing Office.

Fink, Bruce. (1899). Contributions to a Knowledge of the Lichens of Minnesota. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/177988.