Phlyctis argena, known as whitewash lichen

Phlyctis argena, known as whitewash lichen, growing on bark of common aspen in Finland

FinlandHaavanläiskäjäkäläMarchPhlyctisPhlyctis argenaPopulusWhitewash lichenargenaaspenaspen trunkbarkcrustose lichenlichenlichenspowderyspringtree barkwhite