Some flowers grow in clusters, some bloom alone. All flowers, however, have a protected ovary to contain the seeds, and stamens to produce the pollen. Flowers were developed by land plants. Showy petals and sweet nectar are often produced to lure insects to the blossoms. Insects carry the pollen from flower to flower, ensuring exchange of the information encoded in the chromosomes.
Flowers have a well-defined structure.
When the bud appears on the stem, we see the green sepals. Sepals are the green parts that protect a flower bud before it opens. There is usually one sepal for each petal. After the flower opens the sepals can still be seen behind the petals. Nectar is secreted at the base of the petals on the inside of the flower.