The explanation on Mountain Laurel I read -- and I'm sorry I cannot cite the source -- said upper parts of the plant are toxic, but the root that is used for pipes isn't, and perhaps the drying is necessary also, but I didn't read that. It was used during WWII as a briar substitute, and pipe smoking was much more widespread at the time, so pipe smokers were far more numerous, so the "experiment" was run. But it is a good point with unusual materials, the pipe maker has to know what they're doing, no question, both for him/herself and for the buyer. No one has mentioned the now-very-popular morta which is often pictured here on Forums. Someone might review a little about it. I think it is fossiled wood from bogs? Makes a handsome if slightly heavy pipe?