There are only six plant organs: roots, stems, leaves, flowers, seeds, and fruit. Although they are highly variable in appearance, all of these organs are comprised of dermal, ground, and vascular tissues. They can be grouped into two organ systems, the vegetative system and the reproductive system.

Vegetative System
The vegetative organs carry out the functions necessary to the life of individual plants. Plant growth and development, food manufacturing, use, and storage, protection, and support all take place in the roots, stems, and leaves.

Roots are usually found underground. Their main function is to absorb water and nutrients from the soil. Some roots are also important food storage organs. Roots anchor a plant into the ground and help support its weight.

Stems grow primarily above ground. They connect the roots and the leaves, elevate and support the plant, and provide food and water storage.

Leaves are the major site of photosynthesis and gas exchange with the atmosphere. Their function is to provide food for the plant and to dispose of metabolic wastes. Some leaves are highly modified to perform other functions as well, such as protection and reproduction.

Reproductive System
A plant’s reproductive organs and system produce its offspring. The flower is the primary reproductive organ – seeds and fruits are modified flower parts and are not always considered separate organs.

Flowers produce the sex cells and promote pollination, which leads to the formation of a new generation of plants. After fertilization occurs, parts of the flower develop into seeds and fruit.

Seeds contain a plant embryo and a food supply, and are surrounded by a toughened coat. Their function is to produce, protect, and nourish the embryo until conditions are appropriate for germination.

Fruits protect seeds and aid in their dispersal. Built to be carried on the wind or water or consumed by animals, fruits help prevent plant overcrowding and promote colonization.