Question

Ferns and allies (Pteridophyta) - Main characteristics of Fern and allies - Which life stage is dominant: gametophyte or sporophyte? - Groups of Fern and allies and main characteristics of each - Relevance of Ferns and allies

Answer 1

Main characteristics of pteridophytes:

1. First true land plants.
2. Seedless, vascular cryptogams.
3. True roots, stems and leaves present in sporophyte stage. Circinate vernation in leaves.
4. Lifecycle is diplohaplontic.
5. Spores develop in groups of sporangia present on sporophylls.
6. Multicellular and jacketed sex organs.

Sporophyte is the dominant stage.

Pteridophytes are divided into lycopodiopsida (lycophytes) and polypodiopsida (ferns). Lycophytes have dichotomously branching stems with simple leaves. They reproduce by means of spores present in sporangia at the bases of leaves. While ferns are a group of vascular plants. They have branched stems and complex leaves called megaphylls. They reproduce by spores but lack seeds or flowers. They have specialised tissues to conduct water and nutrients,

Relevance of pteridophytes:

• Rhizomes and petioles of Dryopteris is used to make antihelminthic drugs.
• Used as food also eg. sporocarps of Marsilea rich source of starch.
• Ferns are grown as ornamental plants.