What species of plants these were the article doesn't say.
One of them was probably lotus, which was so popular, I think the Egyptians drove it to extinction. It was like when crack users run out of crack today, and try to smoke anything that might be crack because it looks like it — bits of drywall, whatever. :^)
I’ll be darned, it’s not extinct. Maybe they just used all of it in Egypt itself.
https://academic.oup.com/milmed/article/188/7-8/e2689/6338457?login=false
There is also evidence that the Egyptian royal elite enjoyed access to tobacco and cocaine from the Western hemisphere.
Why do you want to know? :)
We have to keep in mind that they had a huge far reaching trade network to other regions. So it could have been some of the already known from other regions. Acacia bark and Syrian Rue was a common hallucinogenic concoction in the middle east. The Amanita Muscaria mushroom was a really big deal all over back then. And I am sure they had opium and others imported.
There’s a link in the article to the study, which does list the plants identified.
Here is a link to the paper: https://www.nature.com/articles/s41598-024-78721-8
Our analyses revealed traces of Peganum harmala, Nimphaea nouchali var. caerulea, and a plant of the Cleome genus, all of which are traditionally proven to have psychotropic and medicinal properties.
Peganum harmala would be Rue tea. They trip on it to this day IIRC.