Plant makes holes in leaves to survive

The Swiss cheese plant, often grown as a houseplant, has leaves full of holes to help it survive in its shady rainforest environment, a U.S. researcher says. The Swiss cheese plant Monstera deliciosa lives in the dark lower levels of tropical rainforests. Writing in the American Naturalist, Christopher Muir of the University of Indiana says the familiar hole-riddled leaves allow the plants to capture sunlight more efficiently. Although a leaf with holes will miss some sunlight because it passes through the holes, he said, solid leaves with the same surface area present less space, restricting the amount of sunlight they are exposed to. A leaf with the same surface area but riddled with holes would contact sunlight more regularly because it presents more space, he said, and would be better equipped in shady rainforests to capture unpredictable shafts of sunlight known as "sunflecks" for photosynthesis. Monstera deliciosa is an epiphyte, or air plant, that attaches to host trees and climbs upward. "They parasitize the trunk and branches of their host plants to climb higher in the canopy where there is more sunlight," Muir told BBC Nature. When it reaches the higher levels it begins to develop the holes in its leaves, he said.