Commensalism benefits one organism and does not harm the other. For example, epiphytic orchids. This interaction benefits orchids as it allows them to grow on top of the trees. This prevents the orchids from being walked on or eaten by ground-dwelling organisms. It also allows the orchids to receive more sunlight for photosynthesis. Since, the orchids receive nutrients from the air and compost on the trees, they do not harm nor benefit the plants on which they grow.