The main organs of seed plants include the roots, stems, and leaves.

Roots are hair-like structures that are formed in vascular plants. They have a similar function with rhizoids. They anchor the body of the plants to the soil and help absorb the water and nutrients.

Stems are the structural axes found in plants. They serve as the plant’s support and transport system.

Leaves are the broad and flat surfaces found in plants that are used in photosynthesis. It protects the plant from water loss by retaining the water and letting the exchange of gases take place.

**Dermal tissue:** root hair cells that absorb water and on the underside of leaves to regulate water loss and gas exchange

**Vascular tissue:** is found throughout the plant in order to transport water and nutrients

**Ground tissue:** is found mainly in plants and roots because they are between the dermal and the vascular tissues

The **vascular tissue** is composed of xylem and phloem that transports, water, nutrients, and minerals throughout the plant. The xylem functions in the transport of water and other minerals present in the roots up to other parts of the plant, while the phloem transports sugar and amino acids between the leaves and other parts of the plants.

Aside from function, these two tissues have varying cell compositions–Xylem is composed of tracheids and vessel elements, while phloem is made up of sieve tube elements and companion cells.

**Meristem** or **Meristematic tissue** is a kind of tissue found in plants that consist of undifferentiated cells that are capable of cell division. Meristem can form into all kinds of tissues and organs that are present in plants.

The cells that are found between the dermal and vascular tissues are called the ground tissues and of these is called **collenchyma**.
**Collenchyma** is a ground tissue composed of cells that are strong and flexible which help in the support of huge plants. Hence, if there is a plant that has heavy leaves you would expect to find a lot of collenchyma cells in that species.

Collenchyma

In the xylem tissue of plants, the specialized cells found are the tracheids and the vessel elements. The tracheids are the elongated cells found in the xylem tissue, while the vessel elements are the shorter and wider cells in the xylem tissue. The roots, stems, and leaves of a plant have these cells form interconnected channels in order for the water to reach all the parts of the plants. Both tracheids and vessel elements are involved in the movement of water throughout the plant.