I had an argument with a friend way back when Pokemon first came out. He thought I was wrong when I referred to Pokemon like Vileplume and Venusaur as ‘Grass-Type’ because he thought the type was called ‘Leaf-Type.’ Someone confirmed I was right and that was the end of that. But that’s something that stuck with me. Wouldn’t ‘Leaf-Type’ make a little more sense? Or even better, calling it ‘Wood-Type?’
I think “Plant-type” would have made the most sense, really. A lot of the languages that the games are translated into go that way, actually – Type Plante in French, Typ Pflanze in German, Tipo Planta in Spanish. The Japanese 草 or くさ (kusa) really does seem to literally mean “grass” though, as far as I can tell, and Grass is what it’s been for twenty years now, so I doubt they’re ever likely to change it at this point.