Organ
/ˈɔrɡən/
Definition
In botany, an organ is a distinct plant structure made of different tissues that work together for a specific function. Roots, stems, leaves, flowers, fruits, and seeds are plant organs. Each differs from a tissue, which is a group of similar cells, because an organ combines several tissue types into one functional unit involved in support, transport, photosynthesis, reproduction, or storage.
Function in Plants
- Division of labor: In plants, each organ supports a distinct set of jobs, such as capturing light, absorbing water, anchoring the plant, or producing seeds. This separation helps the whole plant function efficiently.
- Built from tissues: Every organ is made of several tissues working together. For example, vascular tissue moves water, minerals, and sugars, while protective outer tissues reduce water loss and physical damage.
- Key to identification: Botanists often identify plants by the form and arrangement of each organ, especially leaves, flowers, fruits, and roots. Features such as shape, symmetry, and attachment can separate one species from another.
- Useful in gardening: Knowing which organ is affected helps with diagnosis and care. Root problems can point to watering or soil issues, while leaf or flower damage may suggest pests, disease, light stress, or nutrient imbalance.
Related Terms
Root
Root refers to the plant organ, usually below ground, that anchors the plant and absorbs water and dissolved minerals…
Stem
Stem refers to the main aboveground plant structure that supports leaves, buds, flowers, and fruits, and connects them…
Leaf
Leaf refers to a plant organ, usually flat and green, that grows from the stem or a branch and is specialized for…
Flower
Flower is the reproductive structure of a flowering plant, usually containing stamens, which produce pollen, and one or…
Vascular tissue
Vascular tissue is the plant transport system, made of xylem and phloem. Xylem carries water and dissolved minerals…
Cortex
Cortex refers to the layer of mostly ground tissue found between the epidermis, the outer protective layer, and the…
Epidermis
Epidermis is the outermost layer of cells covering young leaves, stems, roots, flowers, fruits, and seeds. It is a…
Meristem
Meristem is plant tissue made of undifferentiated cells that keep dividing to produce new cells. It is the source of…