Plantwatch: the ingenious fly trap hiding in Britain’s hedgerows

One of Britain’s most remarkable plants is in bloom along hedgerows and woodlands. The cuckoopint, or lords-and-ladies, (Arum maculatum) has a purple poker sticking up provocatively as an advertisement to passing flies. The poker is partially cloaked in a green wrapper like a florist’s bouquet, pinched into a small bowl at the bottom where the small flowers are concealed and when the flowers are ready for pollination, the poker does something extraordinary – it warms up and gives off a scent of pee, an irresistible lure to attract small flies into thinking there’s rotten food for them.

It is a fraud, and as the flies crawl into the chamber at the bottom they become imprisoned by a ring of hairs pointing downwards. When the female flowers are pollinated and male flowers shed pollen, the hairs wither and set the flies free, carrying pollen to another bloom where they get trapped all over again.

Even more spectacular is the related titan arum, Amorphophallus titanum, native to western Sumatra, with a giant inflorescence standing some 7ft (2.1 metres) tall and a huge phallic poker. Again, flies are fooled into thinking there is a meal for them, get trapped and are only released when they have pollinated the flowers.