Why, Muir wondered, would this large-leafed plant punch windows in its foliage? Searching for a plausible evolutionary explanation, he considered where the plant naturally grows: in thick tropical forests, clinging to the trunks of trees about midway between ground and canopy. Might the holes somehow help Monstera capture the sparse, dappled sunlight that filters down through the thick trees?
Muir proposed to solve the puzzle by creating a mathematical model that captures the relationship between a leaf’s shape, size and ability to intercept stray glints of sunlight that filter through the canopy. He saw that surface area wasn’t everything: By extending a leaf’s overall size while keeping living, energy-greedy matter to a minimum, the plant increases the odds that at least some of the splotchy sunlight will strike each leaf.
It’s a smart strategy. “If you have some resources you’re going to allocate to make a leaf, you can make it smaller but completely filled in, or make windows and take up a larger area,” Muir says. “If light is relatively random, it makes sense to spread the leaf area you have … to give you more chances to intercept those sun flecks.
[This article originally appeared in print as "O Holey Leaf."]