A tepal is one of the outer parts of a flower. The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated, as in Magnolia, or because, although it is possible to distinguish an outer whorl of sepals from an inner whorl of petals, the sepals and petals have similar appearance to one another. The term was first proposed by Augustin Pyramus de Candolle in 1827 and was constructed by analogy with the terms "petal" and "sepal".
A Lilium flower showing the six tepals: the outer three are sepals and the inner three are petals.
Flowers of Magnolia × alba showing tepals in various stages of development
Tepals of Magnolia × wieseneri
A hellebore flower showing the petaloid sepals
A flower, also known as a bloom or blossom, is the reproductive structure found in flowering plants. Flowers consist of a combination of vegetative organs – sepals that enclose and protect the developing flower, petals that attract pollinators, and reproductive organs that produce gametophytes, which in flowering plants produce gametes. The male gametophytes, which produce sperm, are enclosed within pollen grains produced in the anthers. The female gametophytes are contained within the ovules produced in the carpels.
Reproductive parts of Easter Lily (Lilium longiflorum). 1. Stigma, 2. Style, 3. Stamens, 4. Filament, 5. Petal
The calla lily is not a single flower. It is actually an inflorescence of tiny flowers pressed together on a central stalk that is surrounded by a large petal-like bract.
Grains of pollen sticking to this bee will be transferred to the next flower it visits.
Ophrys apifera, a bee orchid, which has evolved over many generations to mimic a female bee.
