Flowers

Flowers are unusual in the fact that they contain both male and female reproductive organs. Since plants are immobile organisms, however, most must rely on external agents (such as insects, birds, or wind) for fer-tilization.

Sepals -these leaflike units are found on the outside of the bud or on the underside of the open flower. They protect the flower bud from drying out. Some sepals have spines or chemicals that ward off predators.

Petals -these units, which come in a variety of shapes and colors, attract pollinators and are usually dropped shortly after pollination occurs.

Nectar - this substance, which also attracts pollinators, contains varying amounts of sugar and proteins that can be secreted by any of the floral organs. It usually collects inside the flower, near the base of the cup formed by the flower parts.