Flower

**Flower Etymology and Morphology**:
– The term ‘flower’ originated from the Latin name of the Italian goddess of flowers, Flora.
– In the 17th century, ‘blossom’ split from the term ‘flower’.
– Flowers consist of vegetative parts like petals and reproductive parts like calyx, corolla, androecium, and gynoecium.
– The calyx comprises sepals, the outermost whorl of the flower, while the corolla comprises petals, the innermost whorl.
– Androecium consists of stamens, including anthers and filaments, while gynoecium consists of carpels, including stigma, style, and ovary.

**Perianth and Reproductive Structures**:
– Calyx and corolla together form the perianth.
– Sepals in the calyx are leaf-like and protective, while petals in the corolla are colored, scented, and aid in pollination.
– Androecium contains stamens, the pollen-producing male parts, and gynoecium contains carpels, the female parts.
– Carpels can occur in one or several whorls and may fuse to form a pistil.
– Some flowers exhibit variations in structure, symmetry, and sexual expression, with majority having both pistils and stamens.

**Flower Development and Transition**:
– Flowers develop on modified shoots or axes from determinate apical meristems.
– Transition to flowering is a crucial phase change in a plant’s life cycle influenced by endogenous and environmental cues.
– Vernalization is necessary for many plants for flowering, and molecular signals like Florigen and Constans play key roles.
– The ABC model describes gene interactions determining floral organ development, with A genes leading to sepal formation, B genes to petal formation, and C genes to stamen and carpel formation.
– Loss of B gene function can lead to aberrant flower development.

**Inflorescence and Floral Diagrams**:
– Flowers have specialized structures like nectaries that attract pollinators but are not considered separate organs.
– Inflorescence refers to a cluster of tiny flowers on a central stalk surrounded by bracts.
– Floral formulae and diagrams provide detailed information about flower structure in a concise form.
– Floral diagrams depict the relative positions of various organs and structural details.
– Flowers develop from compressed internodes with highly modified leaves and may resemble modified stems.

**Pollination and Flower Function**:
– Flowers play a crucial role in plant reproduction, being heterosporous and producing male and female gametophytes.
– Pollination is the process of sperm joining ovules, facilitated by various factors like wind, water, animals, and insects.
– Flowers have specific designs to aid in pollen transfer between plants, and pollination biology studies this process.
– Biotic pollination involves interactions with insects, birds, bats, and other organisms, while abiotic pollination occurs through wind or water.
– Mechanisms of pollination include cross-pollination for genetic diversity and self-pollination, which can lead to inbreeding depression in plants.

Flower (Wikipedia)

For other uses, see Flower (disambiguation).

"Floral" redirects here. For other uses, see Floral (disambiguation).

A flower, also known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). 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.

Most flowering plants depend on animals, such as bees, moths, and butterflies, to transfer their pollen between different flowers, and have evolved to attract these pollinators by various strategies, including brightly colored, conspicuous petals, attractive scents, and the production of nectar, a food source for pollinators. In this way, many flowering plants have co-evolved with pollinators to be mutually dependent on services they provide to one another—in the plant's case, a means of reproduction; in the pollinator's case, a source of food.

When pollen from the anther of a flower is deposited on the stigma, this is called pollination. Some flowers may self-pollinate, producing seed using pollen from a different flower of the same plant, but others have mechanisms to prevent self-pollination and rely on cross-pollination, 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 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. This pollination does not require an investment from the plant to provide nectar and pollen as food for pollinators. Some flowers produce diaspores without fertilization (parthenocarpy). After fertilization, the ovary of the flower develops into fruit containing seeds.

Flowers have long been appreciated by humans for their beauty and pleasant scents, and also hold cultural significance as religious, ritual, or symbolic objects, or sources of medicine and food.