One source says purplestem angelica is our tallest native herb. It does grow close to three meters in good habitat. But you have to be careful about such things. I've seen native sunflowers eleven feet tall. And as soon as you say something's tallest, you'll start seeing short ones. Same goes for biggest, smallest, and so forth. In any case, angelica stands out almost anytime you see it. Here's one in autumn in Ives Fen.