The cast-iron plant’s flowers bloom just above the surface of the soil and are often buried. They may mimic mushrooms and serve to attract a surprising pollinator
THERE is a plant whose flowers bloom almost underground – and that might be how it lures in its favourite pollinators, mushroom-eating flies.
The cast-iron plant (Aspidistra elatior ) has drab flowers that are often buried in leaf litter. Biologists have long been puzzled about how these subterranean flowers are pollinated. Slugs, small crustaceans and insect-like springtails have all been named as possible candidates.
To find out, Kenji Suetsugu at Kobe University and Masahiro Sueyoshi at the Forestry and Forest Products Research Institute in Tsukuba studied wild cast-iron plants. “No one had conducted direct observations in the natural habitat,” says Suetsugu.
The pair went to Japan’s Kuroshima Island, where the plants are common. Over two years, they noted the visitors to flowers, and counted how many became fruit each autumn.
While many species visited, fungus gnats were the best pollinators. These small, mushroom-eating flies