In botany, thelabellum (orlip) is the part of the flower of anorchid orCanna, or other less-known genera, that serves to attractinsects, whichpollinate the flower, and acts as a landing platform for them.
Labellum (plural:labella) is the Latin diminutive oflabrum, meaning lip.
The labellum is a modified petal and can be distinguished from the otherpetals and from thesepals 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.[1]
In orchids, the labellum is the modified median petal that sits opposite from the fertileanther and usually highly modified from the otherperianth segments. It is often united with thecolumn and can be hinged or movable, facilitating pollination. Often, the orchid labellum is divided into three or more lobes. Some have modified fleshy lumps on the upper surface generally referred to as thecallus (plural:calli), with some being divided into multiple ridges or a centralkeel. When the callus is flat and broad, it is sometimes called a plate, which can have fringed margins. The callus can be highly modified with striking colors that may aid in pollinator deceit and mimicry.[2][3]
The labellum in orchids is often large and complex enough that terminology describing relative positions for structures on it becomes useful: thehypochile is the basal portion nearer the connection with the rest of the flower, themesochile is the middle portion, and theepichile is the distal portion.[2]
