One of the two divisions of a gamosepalous calyx or a zygomorphic corolla that is divided into an upper (posterior) and lower (anterior) portion;

(In orchids) labellum or lowest petal, usually larger and different in shape from the two lateral ones.

Either of the two fleshy, full-blooded margins of the mouth.

The principal lobes of a bilabiate corolla or calyx; also the peculiar petal of the orchids.

A broad division at the tip of a tubular, bilaterally symmetrical flower.

The upper or lower segment of an irregular (or asymmetrical) flower.

One of the two parts of a zygomorphic bilabiate flower, or the labellum in Orchidaceae.

The lower (and sometimes also t he upper) lobe of the corolla (or sometimes calyx) of an irregular flower.

Each of two fleshy muscular parts round the edge of the mouth.

An edge of flesh round an opening.

In orchids, the same as labellum. In many tubular flowers, the upper and lower lobes at the mouth of the flower, where these are evident.

Soft external structures that form the top and bottom borders of the mouth cavity.

One of two soft folds that line the opening to the mouth. The lips move by the action of a muscle that circles the mouth. The lips are covered with thin skin and are lined with mucous membranes. The principal functions are to keep food in the mouth and to help produce speech sounds. Muscles at the outermost corners of the lips are responsible for facial expression.

A soft external structure that forms the boundary of the mouth or opening to the oral cavity.

A pair of pliable folds encircling the entrance to the mouth constitutes the lips. The principal component of the lips is a circular arrangement of muscles crucial for speech production. Additionally, smaller muscles located at the corners of the lips play a role in shaping facial expressions.

Lip disorders encompass conditions such as dry and cracked skin, cheilitis characterized by inflammation, cracking, and dryness, as well as cold sores and lip cancer.

One of two fleshy parts or folds that make up the edges of the mouth.

The perimeter of an aperture or hollow space.