Mosses in the genus Atrichum have a couple of common names, as many plants do. One name is the smoothcap moss. As I mentioned in last week's post, this name describes the lack of hairs on the calyptra of Atrichum, which is contrast to the hairy calyptra of Polytrichum (the hairy capped moss).
The other common name for Atrichum mosses is the catherinea moss. Originally the genus name for this moss was Catherinea. This name was given to these mosses in honor of Catherine II, who was the Empress of Russia from 1762 to 1796. Historically botanists named plants in honor of their wealthy patrons who funded their research. This genus was named by the German botanist Jakob Friedrich Ehrhart. He was a student of Linnaeus, the famous scientist who came up with the system of binomial nomenclature (Genus species).