Central Appalachian Low-Elevation Acidic Nonvascular Cliff / Boulderfield – CEGL004142

Lichens such as the dark brown "rock tripes" Lasallia papulosa and Lasallia pensylvanica, are the earliest life-forms to invade the boulderfields and begin the weathering process. Blackrock, Rockingham County, Shenandoah National Park.