Flowers are brightly colored or patterned and contain a fragrance or nectar when they must attract insects, animals, or birds. In the process of searching for nectar these pollinators will transfer pollen from flower to flower. The stigma contains a chemical which stimulates the pollen, causing it to grow a long tube down the inside of the style to the ovules inside the ovary. The sperm is released by the pollen grain and fertilization typically occurs. If fertilization is successful, the ovule will develop into a seed.
Some plants bear only one flower per stem and are called solitary flowers.
Other plants produce an inflorescence , a term which refers to a cluster of flowers and how they are arranged on a floral stem. Most inflorescences may be classified into two groups, racemes and cymes. In the racemose group, the florets, which are individual flowers in an inflorescence, bloom from the bottom of the stem and progress toward the top. Some examples of racemose inflorescence include spike, raceme, corymb, umbel, and head. A spike is an inflorescence in which many stemless florets are attached to an elongated flower stem or peduncle, an example being gladiolus.