Monographs Details: Orthotrichum malacothecium 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.
Family:Orthotrichaceae
Discussion:

Type: ARGENTINA, tucuman: Nr. Tafi, May 1872, Lorentz s.n. (no type specimen seen).

Characteristics for this species according to Müller (1882) are the exserted capsules and dark calyptrae. It is not possible from the description to settle the taxonomic position of this taxon.