The announcement was made by Simon Clarke, chief secretary to the treasury, on a visit to Kew Gardens, while the UK government continues to host COP26 in Glasgow.

The Herbarium is 170 years old and contains approximately 8.5 million items – including some collected by Charles Darwin – which staff store, catalogue, arrange systematically, and carefully preserve for future generations.  This record is used to identify specimens collected in the field – including by providing DNA samples – and compare newly discovered species with known species. It contains around 95 per cent of vascular plant genera, 60 per cent of fungal genera, and 330,000 type specimens with 25,000 more added each year.

So far, just 12 per cent of the Herbarium collection has been databased, including all type specimens, which have also been imaged. According to Clarke, the £15m cash injection will allow researchers from around the world to access the historic collection free of charge.

“This vital investment will revolutionise research to combat climate change and biodiversity loss,” said Clarke. “By digitising this unique collection, the largest of plant and fungal specimens in the world, we are opening up a vast stockpile of data which will seed a forest of vital research projects across the planet.”

Digitising the Herbarium will ensure it is protected from natural deterioration with age or catastrophic damage (such as by fire).

Richard Deverall, director of Kew Gardens, commented: “I am absolutely delighted that the British government has committed £15m towards the digitisation of Kew’s plant collections and to secure them for future generations through the construction of a new collections laboratory.

“These collections represent knowledge of plant and fungal diversity that will help scientists around the world conserve nature and find solutions to some of the most critical challenges facing humanity.”

Dr Aaron Davis, senior research leader in the crops and global change team at Kew, added: “The collections at Kew are a global resource that help us to understand what is happening to our biodiversity, how climate change is affecting nature, and what we are losing. It was assembled by partners across the world so it is therefore only right that we speed up the process of digitising this data for everyone to use now in tackling species loss and ensuring we are making good choices that are sustainable for people and planet.”

The digitisation project, which is estimated to take four years to complete, will also support ongoing projects at Kew, including mapping endangered tropical plants in East Africa and Madagascar, protecting vital biodiversity.