December 1, 2020

Country diary: dodder is such a pretty parasite

Morwenstow, North Cornwall: Clumps of what look like pink spaghetti are strewn amid the gorse

The topography of the South West Coast Path has more ups and downs than a stockmarket graph, as anyone who has walked sections of this 630-mile trail knows all too well.

The track rises to grassland plateaus, perched on towering cliffs raked by sea breezes, then plunges down steep-sided valleys where streams spill into sheltered coves, before rising again on a rollercoaster route around the western peninsula.

Walking a short length in north Cornwall, I followed the path through a National Trust site at Morwenstow. Skirting twisted seams of rock high above the Atlantic surf, the track dropped into a boggy gorge and then climbed once more. Only a mile into the walk and I was already breaking a sweat, pausing at the trust’s smallest property, Hawker’s Hut – an eccentric Victorian priest’s driftwood shelter set into the cliff face. From here the path fell sharply into a neighbouring valley. Wild thyme and thrift freckled its sides, and trees stunted by westerly winds crouched beside the brook at its base.

Something caught my eye on the south-facing flank – clumps of what looked like pink spaghetti strewn amid the gorse. Closer inspection revealed thin tendrils bearing clusters of tiny white flowers draped over the prickly thickets – as if delicate fronds of seaweed had been blown up from the nearby shoreline and snagged on the dark green spines.

The peculiar plant goes by the name dodder (Cuscuta epithymum), a native parasitic species that taps into vegetation to plunder its nutrient-rich sap. With no need to photosynthesise, the pale, virtually leafless stems lack chlorophyll and look more like upended roots – something they can also do without, as its host supports it in more ways than one.

Mops of the tangled tresses were scattered across the valley side, with some of the sinuous masses several metres in width. Loss of suitable heathland habitat in Britain means this threatened species is now mainly concentrated in the south and west, where it generally parasitises gorse and heather.

Walking the coast path gradients certainly tests one’s fitness, so curious dodder provides a good excuse to stop, catch one’s breath and wonder. And few plants look quite as lazy, sprawled on thick mattresses of gorse, unwinding in the sun.