Okay, slight update here: I made some of the plants. Ten of them at this moment:
-2 grasses, Consciousness and Epiphany: each of them gives your grazing animals the ability to talk or to learn)
- Ambrosia and Nectar: brewable through special reactions I haven't written yet. Their wine will not only be extremely expensive, but it will also buff your dwarves, permanently if you're lucky. But they will be rare, farming them will take a long time and you might want to keep your military ready when you process them...
-Golden and Crystal vines: the Golden Vine grows in non freezing good regions, the Crystal Vine only grows in tundras, mountains and glaciers. They both produce really valuable cloth, but they are rare. Not as rare as Ambrosia and Nectar, but still you won't be seeing them every day
-Leatherleaf: another cloth producing plant with a twist: this one's cloth can only be made through special interactions. It's reasonably valuable, but what sets it apart from other cloths is that you can craft armor and shields out of it. It will be common, too
-Red Kudzu: a common, fast growing plant that can be eaten raw or cooked, or squished into soap and oil. Good for feeding your fort in the early game, but unexceptional otherwise
-Painter's Rose: a plant that gives a reasonably valuable wine and the game's most expensive wine. It will be somewhat uncommon, though
-Fey Nut Bush: you can make mead out of it, you can press it into sugar and its leaves can be cooked.
I'm still working on the frequencies, though
Once I tune them right, I'll be making some regional interactions.