I'm on vacation and prone to doing something completely irrational. In this case I went through all the monster manuals, tomes, catalogs and bestiarys to form a comprehensive list of all the plants, fungi and rock creatures. I tried to keep it to creatures, not constructs. You will find piercers within, but you'll find nary a stone golem. In all I scoured 22 different books. I'm sure I missed one or two and maybe included one that shouldn't be on the list, but give a poor fellow a break.
The reason I did this you ask? I was creating wilderness encounters and though it would be a good idea to have a listing of natural inhabitants that make it so dangerous. I also made myself a makeshift random table as I created these encounters which is included at the bottom of the post and within the list.
A not on my manual selection, even though there is a lot of redundancy in the creatures (Shambling Mound leading the pack with 5 separate entries, the Treant, Quickwood and Yellow Musk Creeper each scoring four), but there are differences in each entry. Not to mention whole books dedicated to the ecology of the so and so. While I did include the AD&D version of monsters I did not list the 3.0 and 4.0 editions. I have no idea why just didn't.
Hope this list is of some use to someone. I plan on using it for another goofy vacation project I will post about soon. And as promised, here is the random table I produced to come up with a variety of encounters. The percentages may not make any sense, nor were they meant to.
Random Wilderness Table
48-56 Roll Twice and Combine
78-83 After Scene (roll again)
88-93 Empty Lair