Delphinium Blue flower spikes in garden borders. Papaver Papaver somniferum the opium poppy with blueish leaves and varied pink to red spotted petals is widespread in gardens, from bird seed and self-sown on waste ground. Could in theory yield drugs from the white latex. Seeds sold for baking and a component of multi-grain bread. Harmless in ordinary quantities.
Fruits are poisonous and very laxative.
If seeking medical advice take along a twig from the tree. Pea-sized dark purple berries, perhaps less strong than the previous with which it may be confused. Polygonum hydropiper Not poisonous but hotter than chilli. Tear a leaf and chew a tiny bit. Don't swallow unless you want to discover why an alternative common name for this plant is 'arse smart'.