Sepal

A sepal sepal or (plural sepals or Sepala ) is a leaf of the outer perianth in the flower of angiosperms. The totality of the sepals of a flower is called a calyx or calyx. From sepals is spoken only in non-uniform blossoms cases, if the perianth is differentiated into calyx and corolla, if not all bloom are similar ( then called the perianth ).

Design and function

The sepals are usually dense and green. Typically, they are deciduous leaf or bract -like, especially in its vascular bundles supply. The cup has the function to protect the flower buds in the state. During bud development, the sepals grow rapidly curved toward each other and touching each other. Through teeth, bonding or through cuticular hairs, the sepals are often linked. The edges are usually pushed over one another. This provides protection for the inside of the bud developing other floral organs is increased.

The arrangement of the sepals is usually in whorls, especially in more primitive families but also spiral, so in Dilleniaceae or Paeoniaceae.

The cup can also change its function and contribute about by the spread of fruit ripening. In composite flowers the calyx is transformed into a fringe of hair, the pappus, which can be used to wind propagation or for attachment to animals. The cup can also take on the function of the Crown as attracting apparatus, but this is usually accompanied by a reduction of the crown, such as the Proteaceae. The chalice is thereby crown-like ( corollinisch ). Another example is the heather.

In various kinship groups, the petals are connected by gradual transitions with the sepals, as in the cactus family ( Cactaceae ) or at the Peony ( Paeoniaceae ).

Historical

The term sepal 1790 commonly used by Necker for a Perianthblatt. According to him, it is a word that Skepe from the ancient Greek word " blanket cover" derives. Ever since A. P. de Candolle 1813 sepal is used in its present meaning.

The word calix has been used by Pliny in today's meaning. Leonhard Fuchs defined calyx 1542 already largely in today's meaning. Jungius 1678 and Ray 1682 call the cup perianthium, logical because, as then, the Corolla was considered a real flower. Since 1700 Tournefort is clear the current role of the calyx.

Evidence

• Flower