Plantwatch: The pharmacy flourishing in gardens and fields

Plants famous for their drugs are out in flower. Perhaps most spectacular is the brilliant red field poppy, making a stunning splash of colour this summer. This common poppy has a type of opiate that was long used for mild pain relief for toothache, earache and sore throats, as well as a mild sedative. But far better known for opiates is the opium poppy, Papaver somniferum, its lilac-coloured flowers infamous from the illegal drugs trade in Afghanistan. But the opium poppy is also grown for pharmaceutical morphine in parts of southern and eastern England, where the soil and climate are just right. Last summer saw a record harvest and the quality of morphine produced now provides some 50% of all the morphine used in the UK. Although the poppies are grown under a Home Office licence, they are no good for making illicit drugs because the variety grown in England needs a good deal of sophisticated refining to make into morphine.

Meadowsweet was the source of another important drug. This plant grows in damp places and is now in bloom with frothy white flower heads with a heady sweet fragrance. Meadowsweet has an especially proud history because it was used for relieving headaches thanks to a substance called salicylic acid. In 1897 these painkiller properties inspired the chemical synthesis of aspirin - named after the plant's old scientific name, Spiraea.