Scottish. Rose as a male forename is very rare - possibly only found in Scotland - and probably derived, as is Ross, from the Gaelic ros, "a headland".
A correspondent [HG] sent this note:
" ... Rose Dempster Fraser from Dornoch, Scotland. His existence is well documented - he ended up in Bermuda. I think the name Rose came from the local surname - Rose ... "
Another correspondent [GB] reports Rose Swanson, a (male) blacksmith, born about 1827 in Keithhall, Scotland, in the 1851 Census at Newmachar, Aberdeenshire, Scotland; and a son, Rose Duncan, on a gravestone in Ellon, Aberdeenshire dated 1833.
A third correspondent [BMcI] notes a Rose Porter, a crofter, born in Aberdeenshire early in the 19th century.