One of the weird side-effects of studying archaeology is that you soon find that some of your friends think of you as nature's drug dealer. For example, about a month before I finished my Masters degree, a friend of mine approached me and asked if I could identify Jimson Weed (aka Datura stramonium), a highly-toxic plant that , under very, very specific preparation and conditions can produce very strange hallucinations, but outside of those very, very specific conditions will kill you. He had been reading (naturally in culture-porn filled New-Age sources) about North American shamanic practices, and specifically about the use of hallucinogens in these practices, and decided that he wanted to have the experience. I told him about the dangers of the plant, and he claimed that these were over-blown by the DEA in order to discourage use (no, no they're not), even claiming to know someone who had used it and not died. I then pointed out that, even if the Jimson Weed didn't kill him, he was talking about recreating a state that, within it's normal religious context, was watched over by practiced people who had a pretty good idea of how to wrangle the person who had taken the drug in order to prevent them from harming themselves, and he was talking about doing it on his own without any real understanding of what effect it would have on his mind. He declared that he was experienced enough with "altered states of consciousness" that he would be fine.
Unless you were raised and trained by Shamans from a group that uses the plant in its ceremonies, the odds of you poisoning yourself while using it are pretty damn high, and there's a decent chance you'll kill your damn fool self. This isn't marijuana. Hell, it's not even crack. This is fucking datura. People historically have made animal poisons out of this plant for a reason! I would not have shown him the plant to begin with, but as the conversation went on and it became increasingly clear that he wasn't willing to accept just how dangerous the plant really is, nor how it might affect him, I informed him that I would not show him the plant not simply for basic legal reasons, but also because I didn't trust him to be safe and therefore would consider it a moral failing on my part to help him find it.
Given that there was a patch of it growing a five minute walk from his front door, I was particularly averse to showing him how to identify it.
Naturally, if these people are going to ask archaeologists about these plants, they will also ask Native Americans. One of my friends, who is a member of a local Native American tribal organization, tells me of a guy she knows, one of the "I would rather use crystals than chemotherapy should I contract cancer, which I won't because cancer is caused by bad vibes which I don't have because I shop at Whole Foods" sorts of people. He had informed her that he wanted to have a vision quest, and to that end he wanted her to supply him with peyote. Naturally, she refused.
Again, we have somebody without any real knowledge of what he is getting himself into asking someone who knows better to supply him with a dangerous plant. In this case, it is made even more absurd by the fact that the guy, who, like me, is as white as a lily, going to somebody who is from a group that he has some really weird misconceptions about in order to get something that he doesn't know how to use in order to experience a ritual from a culture that he knows next to nothing about. Hell, if he'd known anything about the culture, he would have asked for Jimson Weed instead of peyote - he was talking with a Native Californian and not New Mexican, after all.
Most of the folks I know, when asked to show someone one of these plants for their own use, rolls their eyes and tells the person what they can go do with themselves. But I wonder how often someone, whether out of a misplaced desire to be friendly or out of a sense of morbid curiosity, tells the wanna-be shaman how to identify the plants in question. And I wonder how many of the yearly plant deaths are due to this. Probably very few, but I am still curious.