Pteridophyta

The word pteridophyte means a plant with feather-like fronds. Pteridophytes are also called vascular cryptogams because they are non-flowering plants that possess vascular tissues, i.e. xylem and phloem. In Nepal, 31 families, 103 genera and 383 species of ferns have been reported so far. They are truly land plants that grow well in moist, shady and cool places. Some species are aquatic and a few of them are epiphytes.

General characteristics of pteridophytes

• The plant body is a sporophyte, usually differentiated into roots, stem and leaves.
• They are non-flowering plants.
• They possess vascular tissues, i.e. xylem and phloem.
• Reproduction takes place by spores produced inside the sporangia.
• The plants show clear alternation of generation.

Dryopteris

Classification

This fern is commonly found growing in moist and shady places. They are cosmopolitan in distribution. The plant body is a sporophyte which produces spores. The sporophyte is differentiated into root, stem and leaves.

• The root is a true root.
• The stem is highly reduced and underground, called a rhizome.
• The leaf is called a sporophyll as it produces spores.
• The young leaves are highly coiled in structure; such structures are called circinate and are covered with brownish coloured hair or scale-like structures called ramenta.
• The stalk of the leaf is called the petiole.
• The main axis of the leaf is called the rachis.
• The leaf bears leaflets called pinnae. The pinnae are made up of pinnules.
• The entire leaf is also called a frond.