Pitcher plants are all wet

Pitcher plants' primary way of catching prey may have been missed for more than a century because scientists didn't like working in the rain in rainforests, according to Walter Federle, coauthor of a study published in the online edition of PNAS this week.

Until now, researchers believed that pitcher plants—studied since the 17th century, Federle said—captured most insects using waxy crystals making slippery inner walls. However, when Federle's team studied Nepenthes bicalcarata—one of the few species of pitcher plants that have no slippery waxy inner walls but are nevertheless able to capture insects—after a rainfall, they found "lots of ants just falling one after the other into these pitchers," Federle told The Scientist. That was remarkable, he said, because seeing even single insects trapped is usually a very rare event.

The researchers found that the rim of the pitcher plant—one of several carnivorous plants that traps and digests...