Xylem

Xylem is an important plant tissue as it is part of the ‘plumbing’ of a plant. Think of bundles of pipes running along the main axis of stems and roots. It carries water and dissolved substances throughout and consists of…

Complex Tissues

Tissues composed of more than one cell type are generically referred to as complex tissues. Xylem and phloem are the two most important complex tissues in a plant, as their primary functions include the transport of water, ions, and soluble food substances throughout the…

Glandular trichomes

trichomes are external secretory structures, which are present in about 30% of plant species. For instance, the smell of plants is mostly because of the volatile substances released by these structures. Glandular trichomes are commonly multicellular, with glandular cells at the distal end attached…

Osmophores 

Osmophores are secretory structures that produce the fragrance of flowers through secretion of volatile substances. Plants growing in saline habitats (halophytes) have salt glands to secrete ions, which is the best known mechanism for regulating the salt content of plant shoots.

Nectaries 

Nectaries are secretory structures that release sugar-rich solutions made from the substances supplied by the phloem. Two categories can be distinguished: floral nectaries, which are directly associated with pollination, and extrafloral nectaries, which are found on the vegetative parts of the plant. There is a huge variation…

Hydathodes 

Hydathodes are structures that release water with some substances from the interior of the leaf to its surface. This process is called guttation and occurs by water pressure coming from the root. Hydathodes are modifications of some parts of the leaves and are located along…

3. Sclerenchyma tissue

Sclerenchyma cells form sclerenchyma tissue. These cells have thick, tough secondary walls that are embedded with lignin. At maturity, most sclerenchyma cells are dead and function in structure and support. Sclerenchyma cells can occur in two forms:

2. Collenchyma tissue

Collenchyma cells form collenchyma tissue. These cells have a living protoplasm, like parenchyma cells, and may also stay alive for a long period of time. Their main distinguishing difference from parenchyma cells is the increased thickness of their walls. In…

Simple Tissues

There are three basic types named for the type of cell that makes up their composition: (1) parenchyma tissue, (2) collenchyma tissue, and (3) sclerenchyma tissue. Parenchyma tissue Parenchyma cells form parenchyma tissue. Parenchyma cells are the most abundant of cell types and…