So I got to thinking, now that we have this enormous variety of surface plants available, that traditionally one of the most important aspects of herbalism was as medicine. I suggest a simple system of curable syndromes and medicinal herbs that shouldn't be too intrusive or hard to implement, and that I think ties in nicely with Toady's expressed inclination toward more procedural-everything game mechanics.
The changes would be:
* Syndromes get a tag indicating that they are cured by a given edible plant. Can be specified in the raws, but procedural (e.g. FB) syndromes get random cures as well.
* If a dwarf who is currently affected by a syndrome consumes an edible plant, the syndrome effects are removed and a cooldown timer is set preventing the dwarf from being re-infected for a period of time.
* When the above happens, an announcement is output, allowing the player to serendipitously discover the cure for a given syndrome.
* Alternately, the diagnosis job would have a skill-dependent chance of revealing the cure for a syndrome.
Optional enhancements to this mechanic could include:
* If a dwarf has been diagnosed as having a curable syndrome, the next Feed Patient or Eat job relating to that dwarf will first search for an edible item that is/made from the cure plant.
* Some reaction products (I'm thinking Golden Salve here) get a MEDICINAL tag, making them eligible to to be eaten only as part of the above special curing jobs, and possibly get stockpiled in the hospital.
* If it can be done in a suitably lightweight way, track what a dwarf has eaten recently and apply the cure cooldown retroactively, so it becomes possible to proactively inoculate a dwarf against a known syndrome.
* Make syndromes and their cures (e.g. a demon lawgiver's breath, a foul fog) things you can ask about in adventure mode or be told about by the trade liaison.
Just imagine the conversation in the dining hall, as a new migrant asks about the freakish weather outside. Quoth Urist McHealthy: "Well, this place was a stinking pus-coated hellhole for a while. But then that new doctor showed up, and since then everything's been groovy! Eat up now, a rat weed biscuit a day keeps the rotting limbs away!"