Something that's not mentioned in the article is the fact that on May 1st, people can sell Lily of the Valley (never knew this word before today) in the streets of France without licence or authorizations. The flowers has to come from one's garden though, you can't resell.
Weirdest thing. I was watching Outlander last night where the main character talks about Lily of the Valley. Never before have I heard of this plant and yet today, here we are on HN of all places, with a post about LotV.
Weirdest yet is that I finally decided to watch Breaking Bad and the last episode I watched also mentioned Lily of the Valley :-)
Listen to Queen's song of the same name. :)
"...its introduction from Japan to Europe in the Middle Ages"
That's a very long trip to make in the Middle Ages. How did this happen? What sources are there for this? A quick google search came back empty.
I don't have a clear answer to that, but I don't find it hard to believe.
Lots of plants and fruits were brought from the Far East to Europe in ancient or medieval times: for instance, oranges and peaches originated in China. There were a number of trade channels (not to mention military campaigns or migrations) which allowed for that.
Besides, they're plants, so the trip could easily have taken years or decades for all we know.
I'm surprised that this article doesn't touch on that fact that it's poisonous nor did that fact come up in its historical appearances/uses.