Many a year ago 'back in the day' Broccoli was sold as a 'Bunch' which meant that the stalk was still attached and two or three were banded together. More times than I care to remember I'd go out to find that a customer had broken the stalk off so as to not have to pay for it.
NOTE: Technicality that's covered under 'Willful intent to defraud a shopkeeper' which what Shoplifting is covered under as the product was purchased with the stem attached and when it was removed it was depriving the store of the full profit.
Yes it may sound trivial but if you multiply the loss of a single stem across the hundreds of stores day in and day out it adds up--just like while the 1/8" kerf loss on a table saw doesn't seem like much but after 8 passes you've lost a full inch of the board.
With all of this said I never saw a customer prosecuted for removing the stem of a broccoli.
Back to my point--one day I was working and witnessed a woman snap the stalks off of her broccoli so I walked over and asked her why she had removed it since it was supposed to be included in the sale. She responded that she never used the 'tough stems'.
So I pulled out my produce knife, picked up one of the discarded stem then cleaned up the end and showed her the 'treads' that were closest to the outside and told her that those were the tough part. I then peeled the stalk back just past the threads, then cut her a piece to try raw.
She took a bite, then chewed it a bit and said: "Do you know how many dollars worth of those stems I've thrown away"? I smiled and said, yes they are good once you get past those threads.
She put the piece I'd peeled along with the others she'd tossed in the bag along with the broccoli crowns, thanked me and walked away.
If you are at the grocery store look in the 'Salad Section' and you'll find 'Shredded Broccoli' which usually contains carrots--well my friends, that shredded broccoli is from the stalks.
Thus endeth the lesson (Shawn Connery from I believe his movie Highlander)