An Etymological Dictionary of the German Language/Kappes
Kappes, Kappus, m., ‘headed cabbage,’ from the equiv. MidHG. kappaȥ, kappûs, kabeȥ, m. OHG. chabuȥ, chapuȥ, directly connected with Lat. caput, which strangely enough does not appear in MidLat. in the sense of ‘cabbage-head’; Ital. capuccio (hence Fr. cabus and E. cabbage) presumes, however, a MidLat. derivative of caput in the sense of ‘cabbage-head, headed cabbage.’ The naturalisation of the Ital. word in HG. may have been completed in the 7th cent. or so; by that time a number of Lat. names of plants, as well as the art of cookery and gardening introduced from the South, was already firmly established in Germany.