Anyone know where I can locate some specific toxic plants locally?

I know the title sounds weird and probably suspicious, but I promise it's actually normal.

I'm teaching a workshop on edible versus inedible plants and the importance of not eating unknown plants, and my idea for this is to gather plants that look extremely similar, but where one is edible and the other is toxic, to demonstrate the importance of never eating unknown plants, and the safe method for determining if an unknown plant is toxic.

The idea is to display similar looking plants and try to get the participants to correctly identify which is which, mostly to prove the point that you can't unless you have a very good understanding of what's what.

Among these are Queen Anne's Lace, AKA wild carrot, and ground elder, alongside yarrow and hemlock, but the city does a very good job of keeping free of the latter two.

I'm also hoping, if possible, to gather a little bit of Atropa belladonna, as it closely resembles both blueberries and mountain huckleberries but is exceptionally toxic. I know it grows wild in Oregon, but I haven't seen any this far west, mostly in the Cascades.

Before anyone starts giving me warnings in the comments, I am fully aware of the toxicity of these plants. I cultivate Angel's Trumpets and Devil's Trumpets, which are close relatives of belladonna nightshade in the Solanaceae family. I know all the safety protocols and will not allow anybody to touch them. In fact, I'll probably have them in glass so they can't be touched.

If anyone has sighted any of these three plants locally, please let me know. Even if you think you've seen them, or something that resembles them, let me know, and I will check them out.