Rhus glabra (smooth sumac) has a long history of traditional use by various Native American tribes and early settlers for the treatment of external ulcerations and wounds. The astringent properties of the plant, particularly found in its bark and leaves, were commonly applied as poultices or washes to help dry out and heal skin ulcers and sores. Ethnobotanical records, such as those compiled by Daniel Moerman in "Native American Ethnobotany," detail its use for treating sores, burns, and ulcers externally.

The rationale behind this traditional use is primarily due to the high tannin content of Rhus glabra, which imparts astringency, helping to contract tissues and reduce secretions, theoretically promoting wound healing and reducing inflammation. However, while these traditional applications are well-documented, there is little to no modern clinical research specifically validating the efficacy or safety of Rhus glabra preparations for treating external ulcerations. Most modern references to its use rely on historical accounts rather than on scientific trials. Overall, its use for this indication is supported by tradition and phytochemical rationale, but not by robust scientific evidence.