Writing in the Proceedings of the National Academy of Sciences, researchers say the small flowering plant was discovered in sandy soils in a tiny region of the Cerrado, a tropical savanna region in Brazil.
In addition to normal leaves above ground to capture the energy of the sun to convert carbon dioxide into sugars, Philcoxia minensis also has a network of tiny underground leaves, each about the size of a pinhead, which contain glands secreting a sticky mucus that traps tiny nematodes, or roundworms, and starts to digest them.
Researcher Rafael Oliveira, a professor of botany at the State University of Campinas in Sao Paulo, said he learned about Philcoxia from a colleague who had visited the remote site where it lives and described a plant with underground leaves.
"I had never seen a plant with underground leaves before," he said. "It doesn't make a lot of sense to have leaves underground because there is less sunlight -- so we hypothesized they're getting some other kind of benefit from the leaves."
Carnivorous plants are often found in nutrient-deficient environments and add to their protein needs by consuming insects, researchers said.
Barry Rice, a carnivorous plant expert at Sierra College in California, said Philcoxia's sticky underground leaves are a previously unseen and surprising strategy.
"What else have we missed? It never stops to embarrass me that we spend so little on exploring our own planet," he said.