Actually, if you're talking about trees, then "leaved" is a usable word. Still, it takes some context and still ends up sounding a bit kindergarteny.
This would better accomplish its spooky mission if it were clearer which race you're talking about. Elves? The wizards, perhaps? The Men of Minas Tirith and of the North weren't exactly asleep.
Try rephrasing the disclaimer. People won't know if they get it until they read it.
Author's response
Thank you for reading and taking the time to comment. Hmm..."kindergarteny". How many five-year-olds use this language? It is a bit past "Dick and Jane". I should know better than to use archaic terms today. And, I changed this much.
I should have thought that the idea of aeons passing would make it obvious. I truly did not want to dummy it down. It is about the elves. They would be the only ones interested in the effects of something three thousand years later; man would have long forgotten until shaken up, again.
What in the disclaimer needs clarifying? And, what is wrong with getting as you read it? Do you need it spelled out? If this needs that much clarifying, then it is read by the wrong person.