The blackberries glinted in the September sun. My mouth watering, I leant over to pick one. Disappointment. It was watery, flavourless. Further along the field, another bramble tangle advertised its ripe wares. The fruit here looked flavoursome too, but in amongst the blackberries hung the lurid, purple flowers of woody nightshade, a toxic plant. Third time lucky, more brambles by the gate. The crop of this bush was guarded by barbarous-looking thorns. Yet, the moment I popped one in my mouth, it exploded with juiciness. Perfect.