Tongue papilla. Coloured scanning electron micrograph of a papilla on the surface of the tongue. Tongue (lingual) papillae are the numerous nipple-like protruberances that cover the anterior part of the tongue. In the lower half of the frame (rounded) is a circumvallate papilla. Circum- vallate papillae are the largest and least common type of papillae. Most of the tongue's taste buds (unseen) are located within the clefts of these papillae. The rest of the frame is made up of dead epithelial cells being shed from the upper layers of the papilla. This causes the scaly appearance. Magnification: x150 at 6x6cm size.