In drizzly rain, the view southwards from Pinnock hill, with hedges and woodland receding into the distance, faded like a series of watercolour washes: burnt umber, through sepia, to Payne’s grey on the horizon. Despite February’s freakish weather, with its false promise of spring, there was no sign yet of the pale green tint that appears in tree crowns when buds start to burst.
But in woodland beside me sycamore (Acer pseudoplatanus) buds had begun to swell a little, doubling in size since I stood here last week. They are elegant shape-shifters and slowly their squat winter profile, encased in tight green scales, broadens and elongates, becoming as streamlined as a rifle bullet, blushed with purple, until internal pressure becomes irresistible and pristine leaves tumble out.
Miniature leaf primordia were deep inside all winter, pre-packaged, ready for inflation. With the first surge of sap, a conjurer’s sleight of hand, the sudden transformation begins and bare twigs become a green canopy as translucent as stained glass: the magic of spring.
Sycamore is an introduced species, a native of eastern Europe. Nearby, I found red-berried elder (Sambucus racemosa), another alien species, which arrived in the 16th century at about the same time as ubiquitous sycamore, but is mostly confined to northern England and Scotland. I sometimes come here at the tail end of winter, impatient to see its precocious response to the slightest hint of spring. Today it was already in leaf, with flower buds that seemed only a few days away from opening.
In its native North America, red-berried elder inflorescences are visited by hummingbirds; here bumblebees collect their pollen and nectar, and the scarlet berries that follow in July are soon taken by birds that disperse them in their droppings. It may have originally been planted along this woodland edge as game cover.

Botanists classify plants like these, introduced by people since 1500 and forming self-sustaining populations, as neophytes. As time passes, these integrate, accumulate their own dependent fauna – 99 insect species in the case of sycamore – and acquire their own significance in the cycle of the seasons. On this grey day these two provided welcome reassurance of imminent spring, long before primroses had unfurled their petals.