flower, name for the specialized part of a plant containing the
reproductive organs, applied to angiosperms only. A flower may
be thought of as a modified, short, compact branch bearing
lateral appendages. Like twigs, flowers develop from buds, and
the basic floral parts (sepal, petal, stamen, and carpel) are in
actual fact greatly modified leaves. A typical flower is a
concentric arrangement of these parts attached at their base to
the receptacle, the tip of the stem. Outermost is a whorl of
leaflike green sepals (the calyx) encircling a whorl of usually
showy, colored petals (the corolla). Within the corolla the
stamens, bearing anther sacs full of pollen, surround the
central carpels (ovary). Inside the ovary at the base of the
pistil are the ovules, containing the female sex cells; after
fertilization of the egg, the ovule becomes the seed and the
ovary becomes the fruit. The ovary and stamens are termed
essential flower parts, the petals and sepals accessory parts.
The number and arrangement of the flora