Potato history - skip if not interested
I wasn't going to do this, I really wasn't.
But the reaction to my potato gag made me curious enough to go check it on Wikipedia, and I saw Solkan UK's quote there in the first paragraph. But scroll down a little and there's a more precise date, so I now feel forced to share that with everyone.
"In the 16th century, the potato was introduced to Spain (the first record is from Sevilla, around the year 1570) and from there to the rest of Europe, North America, Africa and Asia."
Wikipedia places the end of the mediaeval period in the early 16th century when the Lutherans split from Rome. YMMV and of course any DnD campaign can have any elements it likes from any historical period or region, as well as all the fictional stuff.
also:
"It is believed that the original potato chip recipe was created by Native American/African American chef George Crum, at Moon's Lake House near Saratoga Springs, New York on August 24, 1853."
Though the article on French Fries, which are what we mean by "chips" here in the UK, says that there is a claim that the Spanish were frying sliced-up potatoes in the lifetime of St Teresa of Avila (d 1582). More reliable records of fried-potato recipes from the 18th and 19th centuries.
Interestingly the sweet potato came back with Columbus; you can make chips from that.
I really will shut up now.
On-topic figleaf: Older-edition versions of Arcane Mark used to let you place your personal rune plus a few other characters, which would be ideal for labelling potions by both function and maker.