Nettle has been eaten, drunk and used medicinally across Britain since the Iron Age; it is rich in iron, calcium and vitamins, and was gathered every spring as one of the first green things available after winter.
Meadowsweet was strewn across church floors and great halls at midsummer for its scent; it also contains salicylates, the same compounds from which aspirin was later synthesised, and has been used for centuries to ease headaches and settle the stomach.
Elder was considered one of the most protected trees in the British folk tradition; you asked permission before cutting it, and to fell one without doing so was thought to bring the house bad luck. The elderflower itself has long been used for its gentle diaphoretic properties, drunk as a tea to break a fever.
Raspberry leaf has been used by herbalists for centuries to support the uterus and ease menstrual cramp; it remains in serious herbal practice today.
These are not exotic ingredients. They grow at the field margin, in the damp hollow, along the hedgerow. They have been known and used in this landscape for a very long time - and for good reason.