Experts have pinpointed five plant-based “foods of the future” that could help feed a rapidly growing global population but today are only eaten in localised areas.
A major report by the Royal Botanical Gardens in Kew, London, called the State of the World's Plants and Fungi, says that of the world's 7,039 edible plant species only 417 are regarded as food crops.
Just 15 crop plants contribute to 90 per cent of energy intake of the human race, while more than four billion people rely on rice, maize and wheat in a world where many suffer from malnutrition and experience hunger.
Scientists warned that around 40 per cent of plant species are at risk of extinction.
“The conservation and sustainable use of the widest diversity of crops and varieties is intrinsically linked to sustainable agriculture and food systems,” said Dr Rémi Nono Womdim, deputy director of the Plant Production and Protection Division at the Food and Agriculture Organisation of the United Nations, who contributed to the research.
“We wanted to address these vital issues and highlight the importance of using a broader diversity of crops to ensure a resilient, sustainable and nutritionally rich agricultural future.”
But what are the five edible plants that could be more commonplace in the future?
Akkoub – Gundelia tournefortii
The thistle-like plant Akkoub grows in the eastern Mediterranean and Middle East and its flower heads typically are eaten as a side vegetable. It can be pickled, fried in olive oil and garlic or added to omelette, meat and chickpea dishes.
Experts warn, however, that it must be sustainably grown. “Akkoub is heavily harvested from the wild, which drastically reduces seed availability,” said the report by Kew Gardens.
Pandanus – Pandanus tectorius
A small-trunked tree known as a screw pine, pandanus is found in coastal areas from Hawaii to the Philippines. Its powerful roots enable it to withstand strong winds, salt spray and drought.
The female plant bears a large fruit similar to a pineapple, which can be consumed raw or cooked, while the leaves can also help flavour dishes.
Morama Bean – Tylosema esculentum
A versatile legume and meat substitute found in arid parts of southern Africa that can tolerate drought. Its seeds can be roasted while the beans are often boiled with maize. The beans are also ground into a powder for porridge or a drink and can yield oil, butter and milk.
Chaya – Cnidoscolus aconitifolius
A fast-growing shrub found in the Yucatan Peninsula in southern Mexico, its highly nutritious leaves – sometimes referred to as tree spinach – are popular in Mexican food and a rich source of protein, vitamins, calcium and iron. Chaya leaves must be simmered in water for 20 minutes because they are toxic when consumed raw.
Fonio – Digitaria exilis
A species of grass that grows in West Africa’s savannahs, it is cultivated as a cereal crop and used to make porridge, drinks and couscous. It is high in iron, calcium and several essential amino acids but requires considerable labour to harvest.
Experts say about 40 per cent of the world’s plant species are at risk of extinction, with deforestation, climate change and the threat of new pathogens largely to blame.
“Never before has the biosphere, the thin layer of life we call home, been under such intensive and urgent threat,” said Professor Alexandre Antonelli, the director of science at Kew Gardens.
“Yet this biodiversity sustains our lives. Open your fridge, peek into your medicine cupboard, examine your living room, feel your clothes. For thousands of years, we have searched nature to satisfy our hunger, cure our diseases, build our houses, and make our lives more comfortable,” he said.
Scientists hope the discovery of new plants and fungi – with nearly 4,000 species being unearthed in 2019 – could help the world face its challenges despite the threat to biodiversity.
“People often think that every species has been located and classified but it’s not the case,” said Dr Martin Cheek, a researcher on the Africa and Madagascar team at Kew. “There are still vast numbers of species on this planet that we know nothing about and don’t even have names for.”