I live a sheltered life, so I'd never heard of Kratom. But it seems that this tree from the coffee family ignites controversy in the USA. The leaf can be brewed as tea, smoked or turned into pills and tablets. It has psychotropic properties (but I guess you could say the same for coffee), and has the great advantage of being legal in the USA. Out on the internet you can buy Kratom freely and read books with titles such as 'Everything You Need to Know to Harness the Power of This Potent Plant' - at least for now.
But the FDA reckon it has opioid properties and has been associated with 44 deaths. The American Kratom Association contest that report: 'The FDA is saying people died and they found kratom in their system. It’s like if I drank a Coke and got hit by a truck.' The Drug Enforcement Agency remain silent.
...oh - and by the way, it can become contaminated with Salmonella.