The mushroom-like flower of the cast iron plant is pictured emerging from the soil. Photo by Kobe University
Nov. 15 (UPI) -- Until now, scientists thought slugs and amphipods pollinated the mysterious flowers of cast-iron-plants, native to the southern islands of Japan. But new research suggests fungus gnats are the main pollinators of Aspidistra elatior.
Though native to the islands of Japan, the cast-iron-plant grows all over the world. Its English name recalls its ability to thrive despite neglect, making Aspidistra elatior a popular house plant.
The plants are mostly appreciated for their long, glossy leaves. But the flowers lend the plant a certain strangeness. The thick and fleshy purple flowers appear as if they're half-burrowed in the soil and are often covered by leaf litter.
Many liken the flower's appearance to that of a mushroom, and the latest research suggests its fungal mimicry promotes pollination by mushroom-loving gnats.
Scientists have previously observed slugs regularly visiting Aspidistra elatior. Studies credited the gastropod with pollinating the flower, but the conclusion was based on observations made outside the plant's native habitat.
To clear up the confusion, scientists at Kobe University in Japan studied the log of visitors to Aspidistra elatior plants in their native habitat on the island of Kuroshima.
"We discovered that no slugs visited, and hardly any beach fleas," Kobe professor Suetsugu Kenji said in a news release. "The candidate that emerged as an effective pollinator was the fungus gnat."
Scientists observed the gnats crawling into the center of the flower and picking up pollen.
Researchers published their findings this week in the journal Ecology.
"We believe that the similar appearance of A. elatior and mushroom fruit bodies may help attract fungus gnats," Suetsugu said. "In addition, A. elatior emits a strong musty odor. Therefore, the fungus gnats may be deceived by both visual and chemical mimicry."