Even the etymological family is a mess. They all backtrack to Latin caulis stalk, stem, cabbage stem; but even in closely related language varieties they might mean different plant varieties, like
Galician, general - col wild kale/cabbage/whatever, collards
Galician, south - couva~couve kale
Portuguese - couve kale
Spanish - col cabbage
…and of course people had to reborrow the word from Latin to refer to stems in general, to make the thing even messier. (e.g. PT “caule” stem)
kale caul kohl kål
Even the etymological family is a mess. They all backtrack to Latin caulis stalk, stem, cabbage stem; but even in closely related language varieties they might mean different plant varieties, like
…and of course people had to reborrow the word from Latin to refer to stems in general, to make the thing even messier. (e.g. PT “caule” stem)
Yeah, it’s wild how many times that root has been reborrowed for different vegetable names
The root is the same, but the stems and leaves are all different!