ergot fungus

Why do witches ride brooms?- The real reason why witches are often portrayed as broom-riding old hags comes down to a popular hallucinogenic drug used by people from the 14th century and onward. The drug comes from a fungus called Ergot, and when consumed, it gave the user unpleasant side-effects such as vomiting, nausea and headaches.

Then, a certain class of women known for dabbling in unusual potions and magic aka Witches, started to spread the word that there was a much easier way to get this recreational drug into the blood stream. Rubbing a small amount into the armpits or the fleshy membrane of female genitalia (no lie) could give you enough of a buzz without the bad come-down. So to distribute ergot with maximum effectiveness, witches borrowed a technology from the home: A broom. Specifically, the handle of the broom. And then … you get the idea. And that’s the main origin of the popular image of a witch on a broom.
Why Do Witches Ride Brooms? (NSFW)
You're never going to look at sweeping the same way again.
By Megan Garber

For your consumption on this Halloween/Samhain, a brief history explaining the use if brooms in witch related imagery. It all relates to the fungus Ergot, which has hallucinogenic properties when used in small doses. I’ll quote a brief section of the article but I would give the whole thing a read as it’s not very long.

“So why do the brooms fit into this? Because to achieve their hallucinations, these early drug users needed a distribution method that was a little more complicated than simple ingestion. When consumed, those old-school hallucinogens could cause assorted unpleasantnesses—including nausea, vomiting, and skin irritation. What people realized, though, was that absorbing them through the skin could lead to hallucinations that arrived without the unsavory side effects. And the most receptive areas of the body for that absorption were the sweat glands of the armpits … and the mucus membranes of the genitals.

So people used their developing pharmacological knowledge to produce drug-laden balms—or, yep, “witch’s brews.” And to distribute those salves with maximum effectiveness, these crafty hallucinators borrowed a technology from the home: a broom. Specifically, the handle of the broom. And then … you get the idea.”