Certainly some uses were period - the sagas mention digging for angelica roots, and the oldest Icelandic law texts mention them too. Many farms had angelica gardens and it was the only plant used as a vegetable that was grown here throughout the Middle Ages. And rhubarb and angelica jam. And when his foster brother went to look for him, he saw that orgeir was clinging to an angelica stalk for dear life, with a sheer drop of hundreds of meters into the ocean below. But make sure you get the right species.
Mistakes can be fatal.
I think the worry was over mistaking Angelica for Hemlock. They look very similiar to each other. To candy Angelica, take cut pieces of the stem and soak them in a simple sugar syrup for a couple days. Take them out and let them dry a bit. And rhubarb and angelica jam.