An Etymological Dictionary of the German Language/Borke
Borke, f., ‘bark,’ a LG. loan-word, which is not found in UpG. The proper HG. is Rinde. Comp. LG. barke, Eng. and Dan. bark, OIc. bǫrkr, ‘bark’; Goth. *barkus is not recorded. Its connection with bergen (in the sense of ‘concealing’) may be possible as far as its form is concerned; but on account of Sans. bhûrja, m. ‘birch,’ n. ‘birch-bark,’ its relation to Birke is more probable.