Learn the Different Types of Plant Cells

Cutaway drawing of a eukaryotic plant cell.
Cutaway drawing of a eukaryotic plant cell. Encyclopaedia Britannica/UIG / Getty Images

Plant cells are eukaryotic cells that are similar to animal cells. As a plant matures, its cells become specialized. There are a number of important specialized types of plant cells. Some examples of specialized plant cells are described below.

Parenchyma Cells

Parenchyma cells are usually depicted as the typical plant cell because they are not very specialized. These cells synthesize (by photosynthesis) and store organic products in the plant. Most of the plant's metabolism takes place in these cells. Parenchyma cells compose the middle layer of leaves as well as the outer and inner layers of stems and roots. The soft tissue of fruits is also composed of parenchyma cells.

Collenchyma Cells

Collenchyma Cells
These plant collenchyma cells form supporting tissue. Credit: Ed Reschke/Getty Images

Collenchyma cells have a support function in plants, particularly in young plants. These cells help to support plants while not restraining growth due to their lack of secondary cell walls and the absence of a hardening agent in their primary cell walls.

Sclerenchyma Cells

Sclerenchyma cells also have a support function in plants, but unlike collenchyma cells, they have a hardening agent and are much more rigid. These cells are thick and contain various shapes. Sclerenchyma cells form the hard outer shell of nuts and seeds. They are found in stems, roots, and leaf vascular bundles.

 

Water Conducting Cells

Water conducting cells of xylem also have a support function in plants but unlike collenchyma cells, they have a hardening agent and are much more rigid. Two types of cells compose xylem. They are narrow, hollow cells called tracheids and vessel members. Gymnosperms and seedless vascular plants contain tracheids, while angiosperms contain both tracheids and vessel members.

Sieve Tube Members

Sieve tube cells of phloem conduct organic nutrients such as sugar throughout the plant. Other cell types found in phloem include companion cells, phloem fibres, and parenchyma cells.