This is widespread across eastern North America and Mexico. In Ky. it is found mostly on old spreading limbs and trunks of elms, oaks and other trees (Cranfill 1980). It also occurs on flatter outcrops of limestone, and sometimes shales or sandstones that may accumulate relatively base-rich soil. In general it is most common at sites that probably experience much daily fluctuation in humidity: near lakes, swamps or rivers; and on exposed points or narrow ridges where condensation often occurs at night.