The law governing foraging, the picking of wild plants for your personal use, varies from country to country around the world. You should always check with the authority relevant to your local situation prior to foraging for wild plants. Even in the UK, laws relating to access rights are different in Scotland to those in and England and Wales.
In the UK, all wild plants are given some protection under the law. Under the Wildlife and Countryside Act, 1981, it is illegal to uproot (defined as to ‘dig up or otherwise remove the plant from the land on which it is growing’), any wild plants without permission from the landowner or the occupier of that land. Under the Act, the term ‘plant’ includes algae, lichens and fungi as well the higher plants (e.g. mosses, liverworts and plants that produce seeds).
It is an offence to uproot plants for commercial purposes without authorisation.
Some plants are specially protected. The Wildlife and Countryside Act contains a list of endangered plants, which are protected against intentional picking, uprooting and destruction. These plants are also protected against sale.