Monographs Details: Orthotrichum crenatoerosum Müll.Hal.
Authority: Buck, William R. 1987. Bryostephane Steereana: A Collection of Bryological Papers Presented to William Campbell Steere On The Occasion of His 80th Birthday. Mem. New York Bot. Gard. 45: 1-749.

Type: CHILE. Isla Clarence, May 1882, Spegazzini s.n. (lectotype h).

The lectotype consists of one fertile stem apex and a few free leaves. The leaves have both leaf margins revolute. This character is known from two species from the same area, O. densum and O. bicolor. The name crenato-erosum indicates a relationship with the former taxon which often has irregular undulate margins near the leaf apex. The few leaves present, however, do not reveal this character. Sporophytes are necessary to give a safe judgment since the peristomes are diflferent in the two. Consequently O. crenato-erosum is here regarded as a dubious name.