Syn.: P. leucostoma A. Massal.

On the smooth bark of Carpinus and other trees in shaded forests.

Belgium: Brab.: RRR, Mosan: AR, Ard.: AR, Lorr.: RR.

Luxembourg: Ard.: AR, Lorr.: AR.

France: Boul.: AR, Pic.: R, Lorr.: RR.

Lit.: Boul.: 71, Di: 190, Mü1: 150, NL84: 16, NL97: 53.