An experienced gardener who collapsed and died after tending to a millionaire’s estate may have been the victim of the deadly wolfsbane plant, a coroner has heard.

In a twist worthy of TV programme Midsomer Murders it appeared that Nathan Greenaway, 33, may have brushed against the flower aconitum, also known as Devil’s Helmet and Monkshood, while tending the garden of Millcourt House, owned by retired venture capitalist Christopher Ogilvie Thompson and his wife Katherine.

After collapsing at the million-pound estate, Mr Greenaway was rushed to hospital where despite numerous blood tests, doctors were unable to establish what was wrong and he died from multiple organ failure five days afterwards on 7 September.

It was only after the gardener’s distraught father, Richard, took up investigating his son’s mysterious death that the connection with the deadly plant came to light.

Histopathologist Asmat Mustajab said it was “more likely than not” Mr Greenaway died handling the deadly purple flower to North Hampshire coroner Andrew Bradley.

The toxins of the plant, which is rarely identified as a cause of death despite growing wild across the country, can easily enter the blood if protective clothing is not worn when handling the flower.

The most incredible flowers in the world Show all 9 1 /9 The most incredible flowers in the world The most incredible flowers in the world Most poisonous Most flowers are known for their beauty or fragrance – but some obtain their notoriety by shadier means. With an unassuming nickname like ‘Lily of the Valley’, you might think that Convallaria Majalis was harmless – it certainly looks it, with its charming bell-shaped droops – but this flower, native to Europe, North America and parts of Asia, is incredibly dangerous, secreting poisonous toxins which can be fatal. Common symptoms following exposure to Convallaria Majalis include nausea, vomiting, severe headaches and a slowed heart beat – so it’s no surprise that this deadly plant made its way into the public’s consciousness when arch-villain Walter White used it to poison a child in the hit show Breaking Bad. Mark this flower under ‘one to avoid’! The most incredible flowers in the world The rarest The ‘Ghost Orchid’ is actually less harmful than it sounds. This delicate flower was believed to be extinct until it was re-discovered in recent years and can only be pollinated by one species of insect indigenous to the local area, making it one of the rarest flowers in the world. Finding this flower might prove difficult – it’s mainly found in remote Cuban forests, and only for two months of the year – but it has recently been discovered in the Everglades, so if you’re willing to make a detour while sunning yourself on the beaches of east-coast USA, this flower is well worth the journey thanks to its stunning appearance and gorgeous, sweet fragrance. The most incredible flowers in the world Most carnivorous Plenty of flowers across the world have been known to catch prey – there are many water-based plants which feed off small insects and fish – but the Nepenthes, also known as the Monkey Cup, takes things to the next level. This large plant is native to China, India, Australia, Borneo and Malaysia among other locations (if you’re feeling brave, the most tourist-friendly places to see it are the Seychelles and the Philippines, where it grows freely), can grow up to 15m tall and contains a sticky fluid which can drown its prey. Unbelievably, this genus has been known to trap and digest rats and other small mammals – making it a shoe-in for the top spot in this category. The most incredible flowers in the world The largest If you want to see some serious flower power, you might want to travel to the south of India to see the Talipot palm. With its gigantic size (these monsters can grow up to more than 25ft) and tree-like appearance, you could be forgiven for thinking that this isn’t a flower at all – but it is technically a flower, albeit one that blooms off of tiny branches rather the main stalk. This stunning genus towers above everything around it, so it shouldn’t be easy to spot if you find yourself in India. The most incredible flowers in the world Most terrifying OK, so we’ve established that there are plenty of species of flower that can deliver lethal doses of poison, and a couple that can catch and kill small mammals – but the Devil’s Breath might just top them all when it comes to the fear factor. These modest-looking blooms grow openly in the streets of Bogota, the capital of Colombia, so you might think they are innocent enough – don’t be fooled. The list of effects this flower has been known to induce include hallucinations, seizures, anaphylactic shock, arrhythmia and, most terrifyingly of all, a zombie-like effect rendering the affected person entirely compliant and unable to retain memories – leading to criminal gangs dosing unsuspected stooges with this flower and using them as surrogate criminals to do their bidding. The most incredible flowers in the world Foulest-smelling Murder detectives often say that the worst part of their job is the smell of a de-composing body, claiming that the stench hits the nostrils and never leaves. With that in mind, consider the Corpse Flower. Found in much of south-east Asia, this rare flower’s name comes from its horrendous odour, similar to that of rotting flesh. The Corpse Flower is unusual in that it has no body, stem, leaves or roots, surviving entirely on its vines, so if you get the chance to see one, it will certainly be worth it – just as long as you make sure to keep your distance! If you do want to track this bewitching beast down, your best bet is probably making your way to Surat Thani in the south of Thailand – you can enjoy the dubious charms of this flower in the wild, not too far from popular nightlife hotspots Ko Samui and Ko Pha Ngan. The most incredible flowers in the world Strangest looking There are many beautiful flowers in the world, but what about those that are somehow entrancing without necessarily being attractive in a conventional sense? You can’t help but love the Dracula Simia, native to parts of South America. Take one look at this loveable chap and you won’t be surprised to hear that it is commonly known as the Monkey Orchid. We’ve no idea how bearing a resemblance to a cartoon chimp provides an evolutionary benefit, but if you’re ever in the forests of south-eastern Peru, this little charmer has to go on the itinerary. The most incredible flowers in the world The ugliest We’re not sure why you’d travel the globe to see the world’s most unfortunate looking flower, but whatever your floats your boat – the Welwitschia Mirabilis, indigenous to Namibia, is the ugly duckling of the flora kingdom, with an appearance that is somewhere between ‘burning embers’ and ‘alien reptile’ – but that really is the flower in full bloom! This flower’s personality isn’t much better than its appearance – it’s a carnivore which traps insects in its leaves – so you’ll need plenty of other attractions on your to-do list to make this one worth seeing. The most incredible flowers in the world Most beautiful Possibly the most hotly-contested award is that of most beautiful flower – we all have our favourites, from the gorgeous fuchsia that grows in your garden with its beautiful ballet dancer droplets to the exotic flame lilies of Africa. But surely the most stunning of all flowers is the unforgettable Bleeding Heart. Native to East Asia (if you want to see this captivating species we’d recommend making it part of your itinerary on trips to China and Japan – it’s also found in Siberia and North Korea, but that might prove somewhat tricky!), these spectacular pink and white, heart-shaped flowers are almost too perfect to be true, as if they’ve been designed by a card company to perk up sales around Valentine’s Day!

Tom Wells, from the Chelsea Physic Garden, said to the Times that wolfsbane was one of the most dangerous plants found in Britain’s gardens.

“The roots are where the highest level of poison is found, although it is still found in the flower,” he said. “If there were cuts on his hand, it would enter his bloodstream and affect his heart very quickly.”

In severe cases the poisoning causes heart arrhythmia, paralysis of the heart and respiratory problems. Other symptoms include vomiting, dizziness and diarrhoea.

Mr Greenaway had been one of a small number of staff employed to care for the gardens and house of the South-African born Mr Ogilvie Thompson and wife in Upper Froyle near Alton, Hampshire.

The sprawling Grade-II listed home, which includes staff cottages, a tennis court as well as a complex of other outbuildings, is reached by a long drive. A member of staff, who spoke to the Daily Mail on condition of anonymity, described Mr Greenaway as “a really nice guy who was really good to work with.”

The Greenaway family say they have faced difficulties in getting to the bottom of their son and husband’s death.

Maggie Bloom, who is representing the family, said in the pre-inquest hearing yesterday that the initial blood sample had been destroyed – despite being against hospital policy – and that later samples that were retained could be useless as the poison leaves the body within a day.

The flower's name proper is derived from the Greek ἀκόνιτον, meaning 'without struggle', while toxins extracted from the flower were historically used to kill wolves, lending itself to its more popular title of 'Wolfsbane'.