Here are a few off the top of my head, am I missing any? feel free to share other country’s more obscure plant prohibitions too.
Stimulant:
coca
khat
ephedra (gray area)
Depressant:
poppy
kratom
Phychedelic:
mescaline cacti
sassafras
psilocybin mushrooms
ayahuasca and other dmt plants (gray area?)
Dissociative:
salvia
iboga
(yes I know mushrooms and ayahuasca aren’t plants, but you get my point)
khat is that Somalian speed. Interesting stuff
Witch ones have enough commercial value to legalize?
dried khat as a tea is not addictive and probably would be accepted into greater society quickly
[EDIT: unless you also consider coffee as “addictive”]
I really want to grow ephedra for tea but I’m pretty sure it’s a big no-no. It sucks people had to go and start making meth out of it. The natural herb is incredibly therapeutic.
https://www.nwcb.wa.gov/class-a-noxious-weeds
I have a whole list of illegal plants in Washington. I don’t think any of em can get you high…
In the us, it is technically the substance in the plant that is illegal, not the plant.
Jimson weed is legal, grows everywhere, and is deadly as can be, worst drug ever.
okay than how can we make money on poisonous and/or invasive weeds…or is someone missing the point? prohibition rises profits but only when there is a demand
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A lot of those aren’t illegal, maybe by state. If you want to go down a rabbit hole of entheogens here you go, it’s linked to another site that got into some deep biochemistry. Nature's Herb Forum - A place to discuss all the herbal gifts nature has brought into this world
There was a lot of mystery with the founder as well as some shady business. Warning some information could be outdated and possibly dangerous to health.
It’s not worth the legal risk to sell plants with controlled substances (Khat, Iboga, ect) and the cost to lobby in an attempt to have such things legalized would be very very expensive to fund.
Salvia and Kratom has been openly sold for a long time but the industry is dominated. A few states have specifically regulated Kratom under the Kratom Consumer Protection Act and have affordable licenses available like Arizona, Nevada, Utah, Georgia but I think Utah’s is the easiest and most setup program right now but not alot of people in those states are following the Kratom regulations. Salvia has age restrictions in some states but Kratom is more explicitly legal in the states with the KCPA bill passed. Plants like Blue Lotus, Kava, Kanna and others can be sold as a supplement and in Kava bars and Tea Rooms but In terms of plants in general that have active things? I’d be writing a book long post listing them all.
Fungi:
Ergot
It depends on the language of the law, like with Mescaline, Peyote was specifically made illegal. While San Pedro which contains Mescaline is legal to grow for ornamental uses, there have been several cases of people being arrested for growing it and others for consumption including a case which the judge ruled a user was growing the San Pedro for it’s Mescaline just because he had other drugs in the house and the plant was a “carrier” of the drug because the law is “any mixture or combination of the salts, isomers, blah blah of blah blah” and the charges stuck. Sellers who import DMT containing plants as “dye” have been arrested. But there are also plenty of cases where people get away with it. It really depends on the judge and the whole situation. But I would avoid plants with controlled substances in them even if the plant itself is not considered illegal/allowed for ornamental use. Some other laws are different like cocaine being illegal it also made all “coca” plants containing cocaine to be illegal which has been interpreted to cover the whole family of Coca if it contains cocaine. Also there are specific state laws and federal laws covering mescaline and peyote if your native american aswell as other specifics.
Is ergot actually still around? I’m definitely not looking for any. 
It grows as a fungus on corn
oh yeah! and what about that fungal endophyte in Ipomoea that contains LSA…?
so witch ones are worth legalizing to remove the risk? probably better off lobbying to legalize them all at once don’t you think?
the strains developed through big pharma are the ones with the most commercial value, and yes it is legal for them to do so.
Interesting. There’s a plant that makes LSA, Hawaiian Baby Woodrose, also I think morning glory seeds.
from what hear Hawaiian Baby Woodrose and morning glory do not produce it but rather a fungus on/in the seeds does… Morning glory fungal culture - Advanced Mycology - Shroomery Message Board
and also Acremonium from Stipa robusta