Divisions of Kingdom Plantae
The kingdom Plantae is divided into five main divisions and they are as follows:
These divisions are based on the following criteria:
• Differentiated/Undifferentiated plant body
• Presence/absence of vascular tissues
• With/ without seeds
• Naked seeds/seeds inside fruits
Thallophyta is the first division of the plant kingdom. Algae and fungi are the two main sub-divisions. It also includes bacteria, molds, lichens, and slime.
Features of Thallophyta:
- They have a simple body design with no differentiation into root, stem and leaves.
- They have unicellular reproductive organs.
Bryophyta are known as the amphibians of the plant kingdom. Mosses, hornworts, and liverworts are the three main sub-divisions.
Features of Bryophyta:
- They do not have roots but have crude stems and leaves.
- The roots are replaced by the rhizoids which acts as an anchor.
Pteridophyta are the vascular plants that use spores for reproducing. They are also known as cryptogams as they do not produce flowers and seeds. Ferns, lycophytes, and horsetails are the three main divisions of Pteridophyta.
Features of Pteridophyta:
- They are multicellular. The male sex organ is known as antheridia and the female sex organ is known as archegonia.
- They contain vascular tissues.
Gymnosperms are flowerless plants that produce cones and seeds. The term gymnosperm means ‘naked seeds’. Coniferophyta, cycadophyta, ginkgophyta, and gnetophyta are the four divisions of gymnosperms.
Features of Gymnosperms:
- They are pollinated by the wind.
- They produce needle-like leaves.
Angiosperms are flowering plants. Approximately 80 per cent of the known green plants are covered by the angiosperms. Monocotyledonous and dicotyledonous plants are the two divisions of angiosperms.
Features of Angiosperms:
- They have vascular bundle with xylem and phloem tissues.
- The root system of this division of plant kingdom is fully developed.