I looked some more, apparently we have koolraap en kohlrabi... very confusing (ánd knolraap..which is turnip, which is the word often used in england scotland and northern ireland and Newfoundland for rutabanga.) all the names in that family seems a bit of a mess, and different ones are used in different countries for a variety of these products.
It is like they said, ok we ve got a few of these vegetables which are related and /or lookalike and we ve got these bunch of names... help yourself! Take a pick
Like i recently learned the american robin and european robin are two completely different birds, not the same with a slight twist (that would have after separation). Not even in the same family. As similar as a pigeon and a seagull... only thing in common is the red chest. But I have only ever heard them being called robin, on both sides of the pond. So initially you assume it is the same bird.
secondly the study is rather shaky, they choose a limited amount of items they considered to be powerhouse food and nearly all met the 10%requirement. They picked 46 items and 41 made the cut (all of which (onion, garlic and several berries) besides tangerine were decided to be added to the list alongside the suspected powerhouse foods based on being associated with benefits of the cardiovascular system, )