Pteridophytes: Plant Kingdom NOTES Class 11 / NEET - 2025 / NEET - 2026

FERN

Pteridophytes: An Overview

Introduction hi h

• Pteridophytes include horsetails and ferns.
• Uses: Medicinal purposes, soil-binders, ornamental plants.
• Evolutionary Significance: First terrestrial plants with vascular tissues (xylem and phloem).

Habitat

• Typically found in cool, damp, shady places.
• Some species thrive in sandy-soil conditions.

Life Cycle

• Dominant Phase: Sporophyte (main plant body with root, stem, and leaves).
• Vascular Tissues: Well-differentiated xylem and phloem.
• Leaves:
• Small (microphylls) in Selaginella.
• Large (macrophylls) in ferns.

Reproduction

• Sporangia: Produce spores through meiosis.
• Sporophylls: Leaf-like appendages bearing sporangia.
• Strobili/Cones: Compact structures formed by sporophylls in some species (e.g., Selaginella, Equisetum).

Gametophyte Phase

• Prothallus: Small, multicellular, free-living, photosynthetic thalloid gametophytes.
• Requires cool, damp, shady conditions to grow.
• Sex Organs: Antheridia (male) and archegonia (female).
• Fertilization: Water is essential for the transfer of male gametes (antherozoids) to archegonia.

Spore Types

• Homosporous: Producing one type of spore.
• Heterosporous: Genera like Selaginella and Salvinia produce two types of spores:
• Megaspores: Large, develop into female gametophytes.
• Microspores: Small, develop into male gametophytes.

Seed Habit Evolution

• Female gametophytes are retained on parent sporophytes.
• Zygote development into young embryos occurs within female gametophytes.
• This is a precursor to seed habit, a significant evolutionary step.

Classification

• Psilopsida: e.g., Psilotum
• Lycopsida: e.g., Selaginella, Lycopodium
• Sphenopsida: e.g., Equisetum
• Pteropsida: e.g., Dryopteris, Pteris, Adiantum

Also Read:

• Gymnosperms - NOTES
• Pteridophytes - MCQs