Plantwatch: The insect-eating alpine plant that proves Darwin was right

Study shows alpine plant traps and digests midges – just as the evolutionary biologist predicted back in 1875

In 1875, Charles Darwin predicted that Saxifraga candelabrum, a small alpine plant, could eat insects.

Its leaves, petals and stems are smothered in tiny, sticky hairs and – just as the evolutionary biologist suspected – the sweet glue on the hairs can lure and trap midges before digesting them with an enzyme.

The nitrogen from their remains is absorbed into the plant, which is essential for it to survive in the nutrient-poor soils of the Hengduan mountains in south-west China. The plant was also found to have genes related to those found in carnivorous plants.

The study findings may point to other killer plants that trap insects with sticky hairs and feed off their remains.

The leaves of the wild potatoes Solanum berthaultii and Solanum polyadenium are covered in sticky hairs and trap aphids and some other small pests, potentially opening the way to combine pest control with plant fertiliser.

Other sticky-haired plants may follow a similar approach, according to a study in the Botanical Journal of the Linnean Society.