If the corolla is fused together it is called sympetalous. Although similar to leaves in shape, they are more comparable to stamens in that they form almost simultaneously with one another, but their subsequent growth is delayed. They are often delicate and thin, and are usually coloured, shaped, or scented to encourage pollination. The petals, together the corolla, are almost or completely fiberless leaf-like structures that form the innermost whorl of the perianth. If the calyx is fused together it is called gamosepalous. They may be deciduous, but will more commonly grow on to assist in fruit dispersal. Sepals are often waxy and tough, and grow quickly to protect the flower as it develops. They are leaf-like, in that they have a broad base, stomata, stipules, and chlorophyll. The sepals, collectively called the calyx, are modified leaves that occur on the outermost whorl of the flower. The early word for flower in English was blossom, though it now refers to flowers only of fruit trees. It comes originally from the Latin name of the Italian goddess of flowers, Flora. In addition to facilitating the reproduction of flowering plants, flowers have long been admired and used by humans to bring beauty to the environment, and also as objects of romance, ritual, esotericism, witchcraft, religion, holistic medicine, and as a source of food.įlower is from the Middle English flour, which referred to both the ground grain and the reproductive structure in plants, before splitting off in the 17th century. After fertilization, the ovary of the flower develops into fruit containing seeds. Many flowers have evolved to be attractive to animals, so as to cause them to be vectors for the transfer of pollen. Flowers contain sporangia and are the site where gametophytes develop. Some flowers produce diaspores without fertilization ( parthenocarpy). This pollination does not require an investment from the plant to provide nectar and pollen as food for pollinators. Self-pollination happens in flowers where the stamen and carpel mature at the same time, and are positioned so that the pollen can land on the flower's stigma. Cross-pollination is when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species. Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. There are two types of pollination: self-pollination and cross-pollination. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross- pollination or allow selfing (fusion of sperm and egg from the same flower) when self-pollination occurs. The biological function of a flower is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Selection of differently constructed flowers at different stages of vascular plant developmentĪ flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae).
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