The vascular plants, also named as tracheophytes are plants that have differentiated tissues that help in conduction of water, minerals, and many photosynthetic products. The word Tracheophyta is taken from the Greek word trachea (which means a duct–a vessel in plants).
There are mainly two types of vascular tissue, xylem and phloem, which are responsible for this phenomenon. These tissues help increase the overall size of vascular plants.
Structure of vascular plants
The interior of vascular plants is well ordered, and the alignment of cells is differentiated.
The xylem conveys the water, obtained from the roots to the rest of the plant body, and is composed of lignin (a basic protein) and dead cells. Inside the roots, water is gained into the tissues. The water then again flows towards the xylem and generates an upward pressure. Then the water is utilized for transpirational purposes inside the leaves. The stomata (tiny openings in the plant) ejects the water out of the plant.
Phloem is also a vascular structure that takes the food from photosynthetic cells and conveys it to the rest of the parts of the plant for development or storage purposes. In the aligned pattern, the phloem is present only on one side of the xylem, mostly in the direction of the stem exterior.
Moreover, the phloem, which takes out the energy from the sunlight and modified it into chemical energy to produce glucose, is composed of living cells. These cells assist in the movement of glucose with the help of transport proteins of the plasma membranes. Phloem provides organic solutes to all parts of the plant. Both tissues, xylem, and phloem are interconnected.
Comparison of vascular and non-vascular plants
|Sr. No||Basis of comparison||Vascular plants||Non-vascular plants|
|1||Definition||Vascular plants are those plants that have xylem and phloem for conduction of water and minerals in all parts of plants.||Non-vascular plants are plants in which specialized vascular structures are absent.|
|2||Life cycle||The dominant life cycle in vascular plants is the sporophytic phase, where they give rise to diploid spores.||The dominant life cycle in non-vascular plants is gametophytic phase.|
|3||Cuticles||In vascular plants, leaves and other parts of plants possess cuticles that are a barrier to protect the plant from desiccation.||Non-vascular plants lack cuticles.|
|4||Leaves||True leaves are present which are of distinct shapes and play a vital role in process of photosynthesis.||They do not have true leaves.|
|5||Roots||Vascular plants have deep root channels which anchor the plant and help to obtain nutrients.||Non-vascular plants possess rhizoids instead of roots to support the plant.|
|6||Reproduction||Vascular plants reproduce by seed production.||Non-vascular plants reproduce by formation of spores.|
|7||Examples||Mosses, Ferns, horsetails etc||Mosses, liverworts and hornworts etc|
Examples of vascular plants
- Among lower vascular plants, ferns are the best example.
- Those vascular plants that undergo reproduction using spores are referred to as ferns. This kind of vascular plant is usually characterized as a seedless vascular plant.
- Ferns are found in humid and hot areas. Their sizes also range from very small to relatively tall trees up to 25 meters in altitude.
- A large number of vascular plants reproduce by formation of seeds instead of spores and they are categorized as gymnosperm and angiosperm.
- These are giant trees that are about three to five feet in height.
- These plants are deciduous and distinctive among gymnosperms for producing seed cones in female plants as compare to a group of leaf-life structures (megasporophyll) with seeds in male plants.
Nonvascular plants also termed as bryophytes are plants that lack any particular internal structure such as xylem and phloem to transport water and nutrients. Bryophytes are mostly observed in damp areas because they are devoid of vascular tissues.
Structure of non-vascular plants
Bryophytes do not possess true leaves and roots. Instead of roots, they have thin, filamentous, thread-like structure; rhizoids to attach them to the ground and to obtain water and minerals. The absence of cuticle and vascular tissues permits the passive, fast absorption of water on their whole surface. They get nutrients directly from the environment and divide it from one cell to another, ultimately throughout the plant. Consequently, these plants are mostly small-sized and grow close to the ground.
- Moss is a nonvascular plant found everywhere in the world.
- Mosses are small, thick plants that are similar to green carpets of vegetation.
- Mosses develop in dense bundles, which help them to hold moisture.
- There are about 12,000 known species of moss.
- Few moss species are very small, while others can grow to considerably large size.
- Liverworts are mostly found in a tropical environment.
- Liverworts grow as microscopic, independent leaf-like structure.
- Liverwort species are less common than mosses but are present in almost each land biome.
- Their rhizoids are very delicate, they are devoid of stems, and they are less than 10 centimetres (4 inches) tall.