First, any idea on what it would have tasted like? Granted, when you’re drinking poison I doubt its taste is your primary concern, but I’m curious if any accounts of Conium victims have mentioned its taste.
Second, would a Conium victim have likely felt any pain? Plato’s account in the Wikipedia article doesn’t seem to mention Socrates being in any pain, but for all I know Plato could have been glossing over the more unsavory points.
I thought it might be similar to Hemlock used as tea but I learned those are different species. According to this conium has a parsnip-like taste and a mouse-like smell. Cause of death is respiratory failure, which doesn’t sound pleasant (though not in traditional terms ‘painful’).
This is an article investigating whether Socrates would really have died the way Plato describes it in the Phaedo, ie. quickly and peacefully. The author notes a number of articles by pathologists and classicists who argue that Socrates’ end would actually have been fairly violent and painful, but he himself argues that the description is consistent with what’s likely to have happened. Personally I suspect the “violent and painful” description is more likely, but who knows.