Yes, in the UK you could likewise theoretically get jail time for a first offence although application of the law often boils down to the discretion of the police officer involved. Many of them can't be bothered with the paperwork for this frankly preposterous "offence".
Even if it does get to court, if you've been found picking wild mushrooms ignorance is in this case a valid defence. That is, you didn't know what they were and hoped they were edible but needed to take them home for identification purposes.
This is based on a small amount of case knowledge, I'm not a lawyer so be careful and don't blame me if you end up in jail!
"The UK legal system is the best that money can buy!" - Someone
“There is a way of manipulating matter and energy so as to produce what modern scientists call 'a field of force'. The field acts on the observer and puts him in a privileged position vis-à-vis the universe. From this position he has access to the realities which are ordinarily hidden from us by time and space, matter and energy. This is what we call the Great Work."
― Jacques Bergier, quoting Fulcanelli