Physcia dubia (Hoffm.) Lettau
Annotated by J. Riley. Remarks: With Xanthoria elegans

Montana: Jefferson County: Jefferson County: 1.5 mi south of Asarco plant and East Helena; at microwave tower on hilltop. Elev. 4340 ft.
46.55794° N, 111.9191° W
Coordinate Source: USFS plot database.
Open stand of PIPO, PICO, and POTR on a hilltop facing Asarco plant. Oldest trees are 120 yrs old; most PICO and POTR are dead. Many shrubs have dead stems. Though substrates look old, there are no lichens except for Hypphy at the base of ninebark and a tiny amoung of Xanpol on a rotting log with a yellow crust. Lichens on limestone rock doing well; Xanele is particularly abundant and dominant. Asarco's 10,000 tons/year NOx emissions probably acidified all tree and shrub surfaces, though plant closed 2 years ago. Cows grazing on plot. Slope 34%. Aspect 327°. With Xanthoria elegans. Substrate: crust on rock.

M. Boyll s.n., Aug 17, 2003
OSC, Barcode: OSC-M-268300