Country diary: the spread of the Welsh poppy

Weardale, Co Durham: Over the past five decades it has advanced rapidly through much of lowland England, Scotland and Wales, with gardeners acting as intermediaries

I have probably walked through Backstone Bank wood a dozen times each year, over four decades, but today was the first time I had noticed lemon-yellow flowers of Welsh poppies (Meconopsis cambrica) beside the footpath.

In summer, the familiar native flowers of similar hue in this oak wood are ground-hugging, five-pointed stars of yellow pimpernel, Lysimachia nemorum, a characteristic species of ancient woodland. The arrival of its new companion, rising through the brambles and fern fronds, marks the latest advance of a botanical paradox.