Habitat and Substrate: On trees, especially in moist crevices in rough bark, often with Physcia millegrana.

Rhode Island Status: Uncommon, but scattered records.

Pollution Tolerance: Intermediate to acid rain but tends to thrive in alkaline environments.

Collection Site(s): Headwaters of Wood River, West Greenwich (#5123); Snake Den State Park, Johnston (#5169); Lake Wallum, Burrillville (#5198); Elm Grove Cemetery at Allenton, North Kingstown (#5509).

Notes: Previously reported in Rhode Island by Bennett (1888) and Greene (2000). Specimens #5123, #5169, and #5509 showed obvious signs of distress, possibly due to current air quality, while #5198 appeared healthy, with vigorous growth.