Kelk

Kelk is the Dutch botanical term for the calyx, the outer whorl of a flower that encloses the developing petals. It consists of sepals and, together with the corolla, forms the perianth. In English botanical usage, the term calyx is used for the same structure.

The calyx serves to protect the flower in bud and may help support the petals after blooming. Sepals can be green and leaflike but may also be colored or petaloid, resembling petals in some species. The calyx can be free (each sepal separate), fused into a tube or cup, or include a secondary whorl outside it called an epicalyx in certain plant families.

In many species, the calyx persists as the fruit develops, forming a protective covering around the developing seed or aiding in fruit dispersal; in others it withers away after fertilization. The calyx, together with the corolla, makes up the perianth and is useful in plant identification because its size, color, and degree of fusion vary across taxa.

Naming and usage: The Dutch term kelk is used in botanical descriptions, floriculture, and horticultural labeling to indicate the calyx; this term is closely related to the Latin calyx and the Greek kalux, from which the English word calyx is derived.