Found in western Canada, it was formally described as a new species in 2017 by Trevor Goward, Pradeep Kumar Divakar, María del Carmen Molina, and Ana Crespo.

The type specimen was collected by Goward near the Clearwater River drainage (British Columbia, Canada), where it was found at an elevation of 700 m (2,300 ft) growing on a basalt boulder.

White linear markings called pseudocyphellae appear primarily along the lobe margins, sometimes forming a subtle net-like pattern across the upper surface.

[2] The lichen produces two chemical compounds that can be detected through standard tests: atranorin in the cortex (which gives a yellow reaction with KC) and salazinic acid in the medulla (which turns orange with PD).

[2] Parmelia imbricaria can be distinguished from related species by its combination of marginal pseudocyphellae, abundantly overlapping secondary lobes, and the presence of salazinic acid as its only medullary compound.