Enlarge / Fungus samples are seen on display inside the Fungarium at the Royal Botanic Gardens in Kew, west London in 2023. The Fungarium was founded in 1879 and holds an estimated 380,000 specimens from the UK. (credit: Henry Nicholls/AFP via Getty Images)

It’s hard to miss the headliners at Kew Gardens. The botanical collection in London is home to towering redwoods and giant Amazonian water lilies capable of holding up a small child. Each spring, its huge greenhouses pop with the Technicolor displays of multiple orchid species.

But for the really good stuff at Kew, you have to look below the ground. Tucked underneath a laboratory at the garden’s eastern edge is the fungarium: the largest collection of fungi anywhere in the world. Nestled inside a series of green cardboard boxes are some 1.3 million specimens of fruiting bodies—the parts of the fungi that appear above ground and release spores.