Flowering plants are all angiosperms, the most abundant kind of plant life found on land. Although there are variations, all angiosperms have the same basic kinds of parts, culminating in the flower itself, which is the distinctive characteristic of angiosperms. There aren't any wasted parts on flowering plants, no parts existing for show alone. Even the flower itself, which might seem merely decorative, has a critical purpose.
The roots of a flowering plant grow beneath the ground, taking up oxygen existing in gaps between particles of soil, moisture and nutrients. Roots may be shallow or deep. Besides taking in needed nutrients, roots anchor the plant and support the parts of the plant that live above the soil. Some flowering plants also create food storage devices like tubers, bulbs and corms.
The stem is the main support of the plant. When it is topped by a flower, it's called the floral axis. Besides flowers, leaves grow from the stem. Sometimes these stems are herbaceous, like those of pansies. Other kinds of stems--on roses, for instance--are woody. Some plants have special stems called rhizomes, which grow underground. Runners grow horizontally, either over the ground or under it.
The main function of leaves is to collect sunlight to turn into food with a process called photosynthesis. Leaves' form follows function: leaves are flat to give sunlight a larger surface to hit. Leaves always sprout in a pattern from the main stem or trunk of a flowering plant. The stem that connects the leaf to the main shoot of the plant is called the petiole.
The flower is the sexual part of the plant and itself has different parts--four parts maximum, if the flower is complete--including male and female. The flower is arranged in whorls. Closest to the stem is the calyx, which has some number of sepals, these protecting the developing bud of a flower. Next are the petals, which can be scented and may have special glands to produce nectar to feed various creatures. In return for this perk, creatures pick up pollen. The pollen contains sperm, produced in the male part of the flower, the androecium. This whorl has stamens, which look like stems within a flower, the stamens each topped by anthers where the pollen is created. Pollinators transport pollen to the female part of the flower, the gynoecium, found at the center. The gynoecium consists of a pistil with a stigma on top--which receives the pollen--and an ovary and ovules. Pollinated flowers eventually produce fruit and seed. Not all flowers contain all four possible parts. For instance, a male flower won't contain the gynoecium.