A way I've seen something like this handled in other games is if you get one piece of what you need, you'll unlock recipes. For example, if you pick up copper ore from the surface, you could get a notification saying, "You've unlocked knowledge about copper!", which would enable the parts of the guide about smelting and finish with a hint, "Surely other such metals exist in this world. Maybe there is more you can do yet.". A list of recipes could show question marks over some items and clicking on those could show that copper is used in a crucible with something else (also shown as a question mark) to make something else to clue you into alloys.
So in OP's case, picking up a cattail could provide a message, "You've unlocked knowledge about cattails!" and looking in the guide would all the recipes you can make right away with cattails and also show that there are further recipes for other things not yet discovered.
Just an idea.
