The working and logical plant/wood/etc reactions is a wonderful development. I tried a long time ago to make a plant that can be grown for wood, but it was very clunky and didn't work well (produced 'logs' and no seeds).
Now with all this, it could be done fairly easily.
This plant:
[MATGLOSS_PLANT:TOWER_CAP]
[TILE:5][COLOR:2:0:0]
[NAME:tower-cap][NAME_PLURAL:tower-caps]
[GROWDUR:4000][VALUE:3]
[SEEDNAME:tower-cap spawn][SEED:4:0:1]
[SPRING][SUMMER][AUTUMN][WINTER]
[FREQUENCY:100]
[CLUSTERSIZE:1]
[PREFSTRING:great size]
[WET][DRY][BIOME:SUBTERRANEAN_WATER]
Coupled with this reaction:
[REACTION:PROCESS_WOOD]
[NAME:process tower-caps into logs]
[SMELTER]
[REAGENT:1:PLANT:NONE:TOWER_CAP:NONE]
[PRODUCT:100:1:WOOD:NONE:WOOD:GIANT_SHROOM]
[PRODUCT:100:2:SEEDS:NONE:TOWER_CAP:NONE]
Allows you to grow tower caps. Now, they'll be grown as STACKS of tower caps, but the stack size wouldn't matter except for storage purposes. You'd also have to add the job to the manager to get them taken out of barrels if you stored them in barrels, but you could easily fix that by making a stockpile just for them with no barrels and have the plant stockpiles not accept them. And having to process them with the furnace operating skill makes little sense... but it actually WORKS now, which is great. And you even get enough seeds to keep growing future generations of them. You could just plant large fields of them every spring, and harvest them every winter.
Imagine what we'll be able to do once Toady migrates all of the workshops to the raws? We could have them processed in farmers workshops instead of smelters, which would make much more sense. And think of all the other things: The ability to make *any* material into *any* object by adding the right entries to the workshops.