Recreational herbs

[Enkidoh]

There definetely are, Somnus is the major one mentioned and shown, which appears to be a narcotic similar to opium that is a purple coloured plant - it's sale and use is illegal in Limsa but naturally the trafficing of it is lucrative to the pirate gangs so they continue the trade with impunity. Some of the refugees near Blackbrush Station are also secretly cultivating in in a cave, and the plants appear to glow in the dark. As a drug it has sedative and calming properties similar to opioids, and is highly addictive - signs of somnus addiction and withdrawl can be seen in the eyes of addicts (as stated during the GNB quests).

The chocobo hunters of Tailfeather also cultivate a native herb that appears to be rather like tobacco that they smoke as a calmative (some of the gnath beast quests involve disemenating the herb to the chocobo hunters, and they're grateful when you do, suggesting like tobacco it too is addictive).

Even beastmen have their own herbs they use as recreational drugs that have no affect on people - the sylphs have a plant called milkroot that is highly potent on sylphs (it greatly intoxicates them and is apparently considered a scourge on sylvan society), yet to non-sylphs it's harmless, or at least does not intoxicate them.

Souunsy did an in depth study on all the known herbs and recretational/intoxicating drugs known in Eorzea, but I lack the link to it alas.