@Tych
But that is just using the word Weed. As it's a surname, and as you have said, has no affiliation with his power. But Grass? Which is why I said it's worse than Glass. You could argue that, "he was named before his power was revealed," but Grass Weed is is like Villain Badguy. One could even go as far as stating that it's as bad as some real world equivalents, like Dick Nibbler, Jed I. Knight, B. J. Gobbledick, and etc.
What I'm saying is, dont name your characters after their professions.