Petals and Sepals

• A bud is enclosed and protected by leaf-like structures called sepals that persist at the base of the flower, often as small, green, oval leaves. Within the sepals are the more brightly colored petals. These have evolved to guide pollinators to the important sexual structures at the center. Some even guide with lines and brighter colors at the base. Petals are sometimes fused, elongated or shaped in some way to help their preferred pollinator find the center and complete pollination. Occasionally, as in dogwoods, the sepals have taken on the role of the petals and become larger and colored, while the true flowers within are insignificant. Daisy flowers, on the other hand, are made up of many tiny complete flowers with only the outer ring producing petals, one each.
  
  

Stamens

• Each flower has one or more, sometimes many, stamens, the pollen-producing organs of the flower. The orange or yellow paired sacs at the top are the anthers, where the male cells are packaged into pollen. When ripe, the anthers split, releasing the pollen to the outside where it can be carried to another flower by the wind, by insects, birds or animals.
  
  

Pistil

• The pistil, or carpal, is the entire female part of the flower, consisting of an ovary that contains one or more ovules, a stalk rising up from it called a "style" and a sticky surface at the top called the "stigma." The stigma traps and holds pollen grains. These then send a tube down the style called a pollen tube. Two cell nuclei move down through the tube as it grows, finally reaching the ovules and joining with the embryo cells inside. At this point, fertilization is complete and the seed begins to form.
  
  

Seed Development

• After an ovule is fertilized, it begins to change into a seed. The fertilized embryo becomes surrounded by food-containing structures called the endosperm. These eventually become the seed leaves of the germinating plant, one in Monocots and two in dicots. These give energy to the embryo so it can grow through the soil and begin to make its own food. The wall of the ovule develops into the seed coat, a hard skin that protects the embryo from damage.