An Etymological Dictionary of the German Language/Annotated/Karde
Karde, feminine, ‘fuller's thistle,’ from Middle High German karte, feminine, Old High German charta, feminine, ‘teasel, the instrument made from the thistle and used by cloth-weavers for carding wool.’ The final source is Middle Latin cardus, carduus, ‘thistle’ (French chardon, Italian cardo), the d of the Modern High German word compared with the t of Old High German and Middle High German is due to the word, which was naturalised about the 7th century, being based anew on the Latin form. —