Montana Field Guide

Aspicilia ryrkaipiae is not documented in Montana. Aspicilia ryrkaipiae is a crustose lichen that grows on calcareous rocks in the Arctic region of Alaska, Canada, and Siberia (Thomson 1997). In 1969, lichenologist John W. Thomson collected a specimen from rock along the Yak River in Montana. Specimens were deposited at several herbaria, including the Smithsonian, MIN, and WIS (Consortium of Lichen Herbaria 2025). Years later, the WIS specimen (Thomson 16289) was annotated as "doubt JWT 1985", and appears to be Circinaria contorta (McCune 2014). Until the other specimens can be reviewed, they are assumed to be Circinaria contorta. Thomson, in his book, American Arctic Lichens: Microlichens (1997), did not add the reported Montana specimen to the distribution map for Aspicilia ryrkaipiae. There is the possibility that the species occurs in Washington, but further review is needed (McCune 2017). A conservation status rank is not applicable (SNA) because this lichen is not known to occur in Montana.