花-科普123

花

杂烩百科2023-02-02 19:06:03百科

花(flower)

显花植物（或被子植物）的繁殖器官，尤指那些繁殖结构有特色或色彩鲜艳者。花的大小、形态、颜色及解剖结构千差万别。有的植物花小，并聚生成有特色的簇（花序）。每朵花有一个花轴，上生重要的繁殖结构（雄蕊和雌蕊），和附属结构（花萼及花瓣）；後者还可吸引传粉的昆虫（参阅pollination）和保护雄蕊及雌蕊。典型的花主要由花萼（位於最外层，由萼片构成）、花冠（由花瓣组成，位於花萼内方）、雄蕊和雌蕊构成，紧贴花轴或花托排列。花萼、花冠可具鲜艳的颜色。花的雄性部分是雄蕊，由花丝和花药组成。花药产生花粉。一朵花中有多数雄蕊，总称雄蕊群。雌蕊是花的雌性部分，由子房、长柱形的花柱、花柱顶部接受花粉的柱头所组成。子房内有胚珠。受精後的胚珠发育成种子，子房膨大发育成果实。在世界上大多数文明中，花一直用来象徵美，赠花仍是最流行的社交礼仪之一。

English version：

flower

Reproductive portion of any flowering plant (angiosperm). Popularly, the term applies especially when part or all of the reproductive structure is distinctive in color and form. Flowers present a multitude of combinations of color, size, form, and anatomical arrangement. In some plants, individual flowers are very small and are borne in a distinctive cluster (inflorescence). Each flower consists of a floral axis that bears the essential organs of reproduction (stamens and pistils) and usually accessory organs (sepals and petals); the latter may serve both to attract pollinating insects (see pollination) and to protect the essential organs. Flower parts are arrayed usually in whorls, but sometimes spirally. Four distinct whorls are common: the outer calyx (sepals), the corolla (petals), the androecium (stamens), and, in the center, the gynoecium (pistils). The sepals are usually greenish and often resemble reduced leaves; the petals are usually colorful and showy. Pollen is produced in the stamens. A pollen-receptive stigma rests atop each pistil. The pistil, made up of one or more carpels, encloses an ovary that contains the ovules, or potential seeds. After fertilization, the ovary enlarges to form the fruit. Flowers have been symbols of beauty in most civilizations of the world, and flower giving is still among the most popular of social amenities.