On the one hand, if you have the storage space, why not carry reference materials? I would consider it on a walk. Botany (edible and not) is always of interest, and I can't ever remember the details.

On the other hand, if you are stranded and need to consult a database for the essentials of survival, then you're in trouble. These skills are more than ideas or information; they're conditioned responses ingrained by repetition and practice.

In a longer-term situation, where you're thinking about gathering food, battery life trumps mushrooms every time. A charged cell phone, even turned off with no signal available, sends out a "ping" by which your position can be roughly triangulated. Not something to rely on (takes a while for the bureaucracy to tap into it) but not entirely useless either.