http://www.digitaljournal.com/article/341609

Why are cheese plants full of holes?

Posted Jan 18, 2013 by Tim Sandle
A new research report suggests that the peculiar leaves of the Swiss cheese plant, which form a pattern of holes, have developed to help them to avoid stress.
Swiss cheese plant  a common houseplant
Swiss cheese plant, a common houseplant
The Swiss cheese plant (Monstera deliciosa) is a common household plant. It originates from Central America. The plant is characterized by its perforated leaves.
The plant appears to have developed in a way that allows it to capture sunlight more regularly. This would have allowed it to have survived for long periods in rainforests where there is a great deal of shade. To survive the plant needs to capture unpredictable shafts on sunlight, known as "sunflecks", in order to photosynthesise for energy.
This theory has been put forward by Christopher Muir at the University of Indiana, in Bloomington, U.S. The BBC summarizes that scientist used mathematical models to show that sunflecks explained the unusual leaf shapes and compared leaves with and without holes. The conclusion was that whilst a leaf with holes misses some sunlight, because the light filters through the holes, solid leaves, with the same surface area, take up less space. This means that their access to sunlight is restricted.
As a house plant the Swiss cheese plant grows best between the temperatures of 20–30 °C (68–86 °F) and requires high humidity and shade.
The findings will be published in the journal The American Naturalist.