Tepal

A tepal is a floral segment in a perianth whose parts are not clearly distinguishable as sepals or petals. Tepals are common in flowers with similar-looking outer and inner floral whorls.

Perianth: The collective term for the sepals and petals, or undifferentiated floral segments, surrounding a flower’s reproductive organs. Tepals are the undifferentiated segments of this floral envelope.
Tulip: A bulbous flowering plant genus with large flowers and six similar-looking floral segments. Its six similar segments are a familiar example of tepals.
Floral organ identity: The developmental specification of floral organs as sepals, petals, stamens, or carpels. Tepals develop when outer floral organs lack a clear sepal–petal distinction.
Petaloid: Describing a plant organ that resembles a petal in appearance or function. Tepals are often petaloid even though they are not classified as petals.
Sepal: A usually green outer floral part that protects a developing flower bud. A tepal is not clearly distinct from this outer floral part.
Lily: A genus of bulbous flowering plants whose large flowers commonly have six similar-looking floral segments. The flower’s six segments are not divided into distinct sepals and petals.
ABC model of flower development: A model explaining floral organ identity through combinations of gene activities in concentric flower regions. Its organ-identity framework helps explain how sepals and petals become distinct.
Bract: A modified leaf associated with a flower or inflorescence. Bracts can resemble floral segments but arise outside the flower’s perianth.
Petal: A usually colorful floral part that helps attract pollinators and surrounds reproductive organs. A tepal is not clearly distinct from this inner floral part.
Magnolia: A genus of flowering trees and shrubs with large flowers and undifferentiated or weakly differentiated outer floral parts. Magnolia flowers illustrate how tepal-like parts may grade into one another.

Linked from 14 pages