Pteridophytes are most advanced cryptogams. Vascular tissues are present in the plant body. Therefore pteridophytes are also called vascular cryptogams. The plant body is differentiated into roots, stem and leaves. The ferns are a large group included under pteridophytes.
- Psilopsida- eg: Psilotum
- Lycopsida- eg: Lycopodium, Selag inella etc
- Sphenosida- eg: Equisetum
- Pteridopsida-eg: Nephrolepis, Pteris , Dryopteris etc.
Gymnosperms are naked-seeded plants. The seeds are not enclosed in fruits. They do not produce flowers and they are regarded as primitive seed plants. They include mostly evergreen trees like conifers and cycads.Gymnosperms are divided into three different classes.
- Cycadopsida-eg: Cycas
- Coniferopsida- eg: Pinus, Cedrus etc.
- Gnetopsida-eg: Gnetum
Pteridophytes vs Gymnosperms
|Seedless spore bearing |
|Naked Seeded vascular plants|
Plant body: Sporophyte
|Sporophyte: well differentiated comparatively smaller in size||Sporophyte: well differentiated, woody, large sized trees, shrubs or climbers.|
|Often moisture loving or hygroscopic rarely xeric||With Xerophytic adaptations|
|Stem: often rhizhomatous, underground or close to the soil||Stem: aerial, large and woody|
|Roots: adventitious roots, rarely rhizoids||Roots: tap root system, extensive and elaborate|
|Less advanced stelar system||More advanced stelar system (eustelic)|
|Vessels are absent||Vessels are absent except Gnetum|
|Secondary growth is absent||Prominent Secondary growth from coniferales onwards|
|Independent sporophyte and gametophyte||Gametophyte dependant on sporophytes|
|Gametophyte independent and free living||Gametophyte dependant on sporophytes|
|The gametophyte or prothallus is often monoecious and bears both antheridia and archegonia||Dioceous; separate male and female gmaetophytes|
|Flagellated or ciliated male gamete||Non-flagellated male gamete|
|Pollen tubes are not formed||Pollen tubes are formed|
|Male gametes swim towards female gametes attracted by chemicals(chemotaxis)||Male gamete moves through the pollen tube to the female gamete|
|Water is essential for fertilization||Water is not essential for fertilization and often wind pollinated|
|Megaspores re shed from the sporangia and independent female protahllus develops||Megaspores are retained in the megasporangium.|
|Archegonia with prominent neck canal cell and venter canal cell||Archegonia lacks neck canal cell and venter canal cell. Archegonium is absent in Gnetum.|