Vinegar Leaves? Never heard of it. Let me know how it tastes.

The nearesy thing to vinegar that I can think of is sorrel.

Hi, welcome to GoY, do you mean Trichostema lanceolatum, common name vinegar weed, was used by native Californians as a remedy for colds and fever, and for pain relief, but was also used as a flea and insect repellent, Derek.

as with most of these things. ancestors who ate stuff and survived passed the info on. those that died either warned people as they were dying or the others saw them eating then dying.
welcome to GoY

?????, Derek.

Never heard of vinegar leaves so asked Google.Found this:
https://herbpathy.com/Uses-and-Benefits-of-Vinegar-Cid3050
Isn't google wonderful? The plant mentioned by Derek is not a British plant and the questioner gives his address as UK, so I think Bulba might be right. Check the leaf shapes because they are pretty different from each other.