petal labellum 2010-10-12T10:25:23Z BTO:0004875 BrendaTissueOBO The labellum is part of an Orchid, Canna or other less known flower that serves to attract insects that pollinate the flower, and acts as a landing platform for those insects. The labellum is a modified petal and can be distinguished from the other petals and from the sepals by its large size and its often irregular shape. It is not unusual for the other two petals of an orchid flower to look like the sepals, so that the labellum stands out as distinct. mgr plant labellum