⚠ Version 1 of The Plant List has been superseded.

This name is in version 1.1 of The Plant List, record tro-35174018, with some changes.

Orthotrichum undulatum Hook. & Grev. is a synonym of Macromitrium incurvifolium (Hook. & Grev.) Schwägr.

This name is a synonym of Macromitrium incurvifolium (Hook. & Grev.) Schwägr..

The record derives from Tropicos which reports it as a synonym (record 35174018) with original publication details: Edinburgh J. Sci. 1: 117. pl. 4: O. undulatum 117 1824.