Canola or rapeseed? Groundnut or peanut?

I was going to write about aioli - and I will sometime soon, but as I was poring over the many recipes I have, I started to find considerable divergence in what oils to use in making the mayonnaise base for aioli. Olive oil? Or much more confusingly olive oil and: canola, rapeseed, peanut or groundnut oil? I had in the back of my mind that these four are actually just two and I think, on further investigation I am sort of right but not quite.

Rapeseed is apparently big in the UK. But then when you look into it, you find that what they call rapeseed, though technically rapeseed, is really canola. We call it canola. Rapeseed comes from the Rape plant which is a kind of brassica - the branch of plants that has cabbage and turnip in it - which is a bit off-putting when it comes to the subject of oil But brassicas also includes mustard plants - and we have done this before somewhere, and rape is a type of mustard plant. It's very old but not much used for human consumption until the 20th century when it became quite fashionable until they found that it was actually toxic to humans and so the Americans banned its consumption. And indeed you can't get it here - well Woolworths and Coles don't have it in their inventory. The problem component is called erucic acid. So the Canadians, who grew a lot of it, developed a new strain in the 70s without the erucic acid and called it canola - Canadian oil, low acid - that's how it got its name. Having read an article on the British craze for rapeseed oil I have come to the conclusion that actually they mean canola oil anyway. I don't think the original rapeseed oil is around anymore. Besides it's an unfortunate name isn't it? But canola is currently king of the health people when it comes to cooking with oil I think. Well I didn't look into coconut oil but I cannot believe that is healthy.

But canola is not without its controversy either. For there are GM versions of it which make it disease resistant. And we all know how hostile some are to GM products. Apparently so much so that it represents a mere 20% of the Australian crop. Or thereabouts. Those huge fields of yellow flowers are pretty though. I saw one article that said that Japanese tourists, bored with cherry blossom (how can you be bored with cherry blossom?) come to look at the canola fields. Not as sensational as a field of sunflowers though.

But why can't all the English speaking nations of the world agree on calling it either rapeseed or canola? It causes great confusion to us mere mortals.

Ditto for peanut and groundnuts. Well again, peanuts are a type of groundnut. So I think that when the British talk about groundnut oil they really mean what we call peanut oil. Peanuts and groundnuts grow on low-growing plants - but below the ground - like potatoes I guess. So although they are nutlike, they are actually a legume - though I confess that I thought that legumes (like beans) grew above ground. So I am even more confused.

The more I look into this the more confused I become. One thing I have learnt though, is that apart from Elizabeth David almost everyone says not to use olive oil to make mayonnaise (aioli is a kind of mayonnaise), but to add just a touch of it. I must admit I've only made it with olive oil before, so I shall have to think about this. I guess it depends what you want it to taste like. By the time I write about aioli I might have made up my mind.

And I am not going to look at the scientific evidence on the health benefits of all these different oils either. My tiny mind is not up to it today.