In terms of symbiotic relationships, commensalism is a partnership in which one species benefits without significantly affecting the other. Few cases of such a relationship have been documented, but included among these are epiphytes. Epiphytes are plants that perch and thrive upon other plants. Most abundant in tropical locations, these plants attach often for means of support and more sunlight. Due to their lack of roots and inaccessibility to soil, they use special adaptations to obtain and store water and nutrients, e.g. leaves that absorb organic matter or “tanks” the hold water. Epiphytes are found in several plant groups, including bromeliads, orchids, and ferns.