In this article we will discuss about the similarities and differences between pteridophytes and gymnosperms.
Similarities between Pteridophytes and Gymnosperms:
1. There is a regular heteromorphic alternation of generations.
2. Sporophyte is the predominant plant body and is differentiated into root, stem and leaves.
3. Some pteridophytes and some gymnosperms exhibit air cinate vernation in young leaves.
4. There are no vessels anatomically in both pteridophytes (except Selaginella, Marsilea) and gymnosperms (except Gnetales).
5. Phloem does not have companion cells.
6. Spores are always haploid as they are always a product of meiosis.
7. Some pteridophytes and all gymnosperms are heterosporous.
8. Gametophyte is comparatively a reduced structure in both.
9. In heterosporous pteridophytes and all gymnosperms mega spore is always retained within the mega-sporangium.
10. Sex organs of the gametophytes are always antheridia and archegonia.
11. Spores are produced in strobili or cones (with some exceptions).
12. Root hairs are absent in both.
Differences between Pteridophytes and Gymnosperms:
1. The sporophytic plant body is by and large arborescent in gymnosperms while it is not so in pteridophytes.
2. Roots are adventitious in pteridophytes while they arise from the radicle (tap root) in gymnosperms.
3. Pteridophytes may be homosporous or heterospoers, while all gymnosperms are heterosporous.
4. Most of the pteridophytes have a preference for cool, moist areas, while gymnosperms generally exhibit xeric characters.
5. Branching of the stem is dichotomous in pteridophytes while it is lateral in gymnosperms.
6. Heterospory has never resulted in dioeciousness in the sporophyte in pteridophytes, while it is so in many gymnosperms.
7. Generally secondary growth is absent in pteridophytes, while it is present in gymnosperms.
8. In pteridophytes both microspores and megaspores are released from their respective sporangia, whereas in gymnosperms, megaspore is permanently retained.
9. There is pollination in gymnosperms, while it is absent in pteridophytes.
10. Siphonogamous fertilization (pollen tube development) is seen in only gymnosperms.
11. Male gametes are ciliate in pteridophytes, while they are not in gymnosperms (except for few like cycas).
12. Gymnosperms are seed plants (spermatophytes), while there is no seed in pteridophytes.