• Roses in various stages of opening.John Grant/Photodisc/Getty Images
  
  Angiosperms are plants that depend on flowers to reproduce. The bright showy petals and sweet fragrance encourage bees and other insects, as well as animals, to sip their nectar and help transport pollen from one flower to another. The rose, one of the flashiest flowers in the plant kingdom, goes through the same necessary stages of reproduction as other angiosperms.
  
  

Perfect and Imperfect Flowers

• Most roses are perfect flowers, meaning that they have both male and female sex organs. Roses that have one or the other are called imperfect. When insects visit perfect flowers, sometimes the flower is pollinated by its own pollen. Not all roses bloom on a bush at the same time. This increases the chance that pollen will be carried from one plant to another as the insect travels from bush to bush looking for nectar.
  
  

The Rose Bud

• Roses start out as small green buds. The folded petals are hidden beneath the tightly wrapped green sepals. These sepals protect the growing flower against heavy rains, wind and excessive sunlight. As the petals mature, the bud swells and the sepals loosen, showing a tiny flash of color at the end.
  
  

The Opening Flower

• The sepals continue to open, and the rose unfolds. As the petals stretch outward, the sepals fold back toward the stem and act as a support for the growing flower. The rose petals spread out until the male and female sex organs are visible in the middle of the blossom. The scent from the nectar and the flashy petals provide a clear invitation to its pollination helpers. The goal is for the visiting insect to brush against the anthers, the sticky tips of the male sex organs, and collect some pollen. When the insect visits the next flower, some of that pollen is deposited on the stigma, the tip of the female sex organ.
  
  

The Pollinated Flower

• Once the pollen reaches the stigma, the tiny grains make their way down through a tube called the style to the ovary. The pollen grains fertilize the ovules, which will become the rose seeds. Once the ovules are fertilized, the rose begins to wilt, the petals start to fall off and the base of the flower holding the future seeds starts to swell. Eventually, all that is left is a pod, which when it dries releases the seeds. Roses that have not been pollinated leave just a bare stem behind when they wilt and die.