Ecology. Puna; on rocks. Elevation. 3300-4315 m. Distribution. Bolivia: Cochabamba, La Paz. World range: endemic to the tropical Andes (Peru, Bolivia).
This species is similar to Gertrudiella exhibiting lanceolate leaves, and guide cells in several layers, however according to Zander (1993: 76), D. herzogii differs from that genus, and other species of Didymodon, by the microstomous, eperistomate capsule and medial basal cells transversely resorbed across longitudinal walls to form slits. The type of Trichostomum ferrugineum Herzog hom. illeg. (= Gertrudiella ferruginea Hilp.) was collected by Herzog from Chocayatal.
Specimens. Cochabamba: Herzog 3606; La Paz: Fuentes & Aldana 6614 (HSB, LPB, MO, USZ; det. J.A. Jiménez).