Night-flowering catchfly

Night-flowering catchfly (Silene noctiflora) is an unusual plant in a number of respects, two of which are indicated by its popular name. It grows on arable land and also on wasteland throughout Britain except for the far north.

A single stem, usually unbranched, grows to a maximum height of 24 inches (60 centimetres), with unstalked leaves growing in pairs at intervals up the stem. The plant flowers in July and August, which is when its more remarkable features come into play. The petals, which are pale yellow on the underside, roll up during the day but unroll to reveal their pink or white upperside as dusk approaches. They also release their pleasant scent at the same time.

The reason for this regime is that the plant is mostly pollinated by moths, notably the yellow underwing. This is where the “catchfly” part comes in, because the stems of the plant are covered in sticky hairs. When the moth touches the plant it finds that it cannot get away easily and so is more likely to get covered in pollen, or release any pollen it is already carrying, as it tries to break free.  This it will do, because the plant is not insectivorous and is only interested in temporary prisoners rather than permanent ones.

Another unusual feature of night-flowering catchfly is that the anthers in the flowers only produce pollen several days before the stigmas are ready to receive it. This means that the plant cannot self-pollinate and therefore depends on the moths to do this job for it.

© John Welford