Take a look at MATERIAL_REACTION_PRODUCT for the fruits. That way growths can be made of plant material (though I'd recommend not making them edible), and a single reaction can process all of the special plants.
Here's a peek at how I made gem vines in The Earth Strikes Back mod. There are 24 different plants that use one reaction. In my case the products for each plant form a theme, but that's not required. Yes, the fruit is ridiculously expensive, that's intentional.
[PLANT:VINE_EMERALD]
[NAME:emerald vine][NAME_PLURAL:emerald vines][ADJ:emerald vine]
[USE_MATERIAL_TEMPLATE:STRUCTURAL:STRUCTURAL_PLANT_TEMPLATE]
[MATERIAL_VALUE:3]
[EDIBLE_VERMIN]
[BASIC_MAT:LOCAL_PLANT_MAT:STRUCTURAL]
[USE_MATERIAL_TEMPLATE:FRUIT:FRUIT_TEMPLATE]
[MATERIAL_REACTION_PRODUCT:SPIRIT_MAT:LOCAL_PLANT_MAT:DRINK]
[MATERIAL_REACTION_PRODUCT:SEEDS_MAT:LOCAL_PLANT_MAT:SEED]
[MATERIAL_REACTION_PRODUCT:GEM_MAT:INORGANIC:HIDDEN EMERALD]
[STOCKPILE_PLANT_GROWTH]
[MATERIAL_VALUE:333]
[PICKED_TILE:'%'][PICKED_COLOR:2:6:0][DEAD_PICKED_TILE:182]
[WET][DRY][BIOME:SUBTERRANEAN_WATER][UNDERGROUND_DEPTH:4:4]
[VALUE:3]
[USE_MATERIAL_TEMPLATE:DRINK:PLANT_ALCOHOL_TEMPLATE]
[STATE_NAME_ADJ:ALL_SOLID:frozen emerald spirits]
[STATE_NAME_ADJ:LIQUID:emerald spirits]
[STATE_NAME_ADJ:GAS:boiling emerald spirits]
[STATE_COLOR:ALL:EMERALD]
[MATERIAL_VALUE:2]
[DISPLAY_COLOR:2:0:1]
[EDIBLE_RAW]
[EDIBLE_COOKED]
[PREFIX:NONE]
[DRINK:LOCAL_PLANT_MAT:DRINK]
[SPRING][SUMMER][AUTUMN][WINTER]
[USE_MATERIAL_TEMPLATE:SEED:SEED_TEMPLATE]
[MATERIAL_VALUE:333]
[EDIBLE_VERMIN]
[EDIBLE_COOKED]
[SEED:emerald seed:emerald seeds:6:0:1:LOCAL_PLANT_MAT:SEED]
[FREQUENCY:50]
[CLUSTERSIZE:5]
[PREFSTRING:emerald clusters]
[SHRUB_TILE:18]
[DEAD_SHRUB_TILE:18]
[SHRUB_COLOR:2:2:1]
[DEAD_SHRUB_COLOR:6:0:0]
[GROWTH:FRUIT]
[GROWTH_NAME:emerald cluster:emerald clusters]
[GROWTH_ITEM:PLANT_GROWTH:NONE:LOCAL_PLANT_MAT:FRUIT]
[GROWTH_DENSITY:1000]
[GROWTH_HOST_TILE:BRANCHES_AND_TWIGS]
[GROWTH_TIMING:120000:200000]
[GROWTH_DROPS_OFF_NO_CLOUD]
[GROWTH_PRINT:18:'%':2:14:1:120000:200000:3]
[REACTION:PROCESS_GEM_CLUSTER]
[NAME:brew gem cluster]
[BUILDING:STILL:CUSTOM_G]
[REAGENT:cluster:1:PLANT_GROWTH:NONE:NONE:NONE]
[HAS_MATERIAL_REACTION_PRODUCT:SPIRIT_MAT]
[UNROTTEN]
[REAGENT:barrel/pot:1:NONE:NONE:NONE:NONE]
[EMPTY]
[FOOD_STORAGE_CONTAINER] barrel or any non-absorbing tool with FOOD_STORAGE
[PRESERVE_REAGENT]
[DOES_NOT_DETERMINE_PRODUCT_AMOUNT]
[PRODUCT:100:5:DRINK:NONE:GET_MATERIAL_FROM_REAGENT:cluster:SPIRIT_MAT]
[PRODUCT_TO_CONTAINER:barrel/pot]
[PRODUCT_DIMENSION:150]
[PRODUCT:100:1:SEEDS:NONE:GET_MATERIAL_FROM_REAGENT:cluster:SEEDS_MAT]
[PRODUCT:20:1:ROUGH:NONE:GET_MATERIAL_FROM_REAGENT:cluster:GEM_MAT]
[SKILL:BREWING]
I intentionally used non-standard material names to keep these things out of standard reactions. The inedible fruit can go thru this custom reaction at the still to produce some booze, a seed, and a 20% chance of making a rough gem.
You can go a step further and store the
finished item data in the fruit along with the
material data. That way one fruit can make a bar of steel and another can make a log of oak, all using the same reaction. The details for that are
on the wiki.
Edit: The underground_depth of 4:4 ensures that they never spawn naturally, which is a quirk of the mod (you extract the initial seed from a special kind of mined gem). For your purposes, you probably don't want to copy that bit.