When I read this question, the first thing I thought of was The Magic of Xanth, by Piers Anthony.
Here's the cover of the first book, A Spell for Chameleon:
Xanth (/ˈzænθ/ ZANTH) is a fantasy world created by author Piers Anthony for his Xanth series of novels, also known as The Magic of Xanth. Anthony originally intended for Xanth to be a trilogy, and after the success of the first three books expanded the series to nine books. A devoted fan base persuaded the author to continue writing the series, which is now open-ended.
Each character in the books has a single, unique power, that nobody has ever had before or will again, although powers can overlap.
And things in the book are definitely the way you described - the literal name. Here's Ironwood:
Yet the higher growths were no more promising; the huge metal trunks of ironwood trees crowded against the burned-out boles of ash. Rust and ashes coated the ground around them.
The Magic of Xanth: The Source of the Magic, chapter 7: "Deadly Distaffs"