After coming across an ‘unusual pebble’ on a Welsh beach, budding horticulturalist Evan Smith soon discovered it was in fact a seed from the world’s biggest seed pod.

After successfully germinating the seed at home, the vine rapidly outgrew its supportive bamboo, taking to the curtains, and was nick-named ‘Cliff’. Evan reached out to the Eden Project to home his exotic vine.

Entada gigas is a vine native to Central America, northern South America, the Caribbean and Africa. It produces the world’s longest bean pod, housing the large seeds that are known as sea beans or sea hearts due to their propensity to float for thousands of miles across oceans.

The plant is part of the pea and bean family, Fabaceae, and can yield pods up to two metres in length and 12cm in width. Each gigantic pod can house 10 to 15 seeds, each around 6cm in diameter and 2cm thick.

The seeds can travel for as much as a year, often washing up on shores of northern Europe. It’s likely this seed was carried across the ocean by the Gulf stream, potentially originating 5,000 miles away.

Fourteen-year-old Evan from Swansea found the heart-shaped seed while walking across Three Cliffs Bay with is dad. Upon closer inspection, and following a quick buoyancy test, Evan concluded correctly that this must, in fact, be a seed.

Entada gigas is a fascinating plant with a rich history. The seeds may be found along high tide lines of beaches, but actually germinating the seed takes some knowledge, and a bit of luck in terms of the conditions the seed has endured, as they need warmth to remain viable.

Catherine Cutler, Eden’s interim head of horticulture, said: “We were delighted when Evan contacted us to ask if we might adopt his plant. Plant donations are rarely accepted due to the bio-security risk posed, but Evan and his very special plant caught our imagination, after putting protocols in place we finally could receive the plant. We look forward to introducing Cliff to the Rainforest biome where he should thrive.

In their natural habitat, the woody vines that scramble rapidly from ground level often provide thoroughfares through the canopy for animals and insects, including lizards, snakes, sloths and monkeys – the latter giving the plant the nickname ‘monkey-ladder’.

Today, over 40 species of sea bean can be found washed up on beaches around the British Isles. In Norway and Northern Europe, the seeds were often hollowed out and made into decorative boxes and lockets, or kept by sailors as good luck charms.

Legend has it a sea bean inspired Christopher Columbus to set sail in search of the seed’s origins, leading him to arrive to the Americas.