"Nepenthes macrophylla" differs from both of these species in the structure of its peristome. Although highly developed, the peristome ribs and teeth of "N. macrophylla" are considerably shorter and more widely spaced than those of either "N. edwardsiana" or "N. villosa". The pitcher mouth of "N. macrophylla" is distinctive in that it rises gradually towards the lid, while at the same time not forming a pronounced neck. In addition, the mouth of this species has a much more oblique insertion than its relatives. "Nepenthes macrophylla" is also distinguished by its broad, lid. The lower pitchers of "N. edwardsiana" and "N. macrophylla" are quite similar in shape, although in the latter species the hip is always positioned in the upper portion of the pitcher cup. The upper pitchers of these species are more distinct, with those of "N. macrophylla" being more ovoid and less elongated. As its name suggests, "N. macrophylla" produces very large leaves and these may be twice as long as those of either "N. edwardsiana" or "N. villosa".