Life cycle
- Just like with seed plants and mosses, the life cycle of pteridophytes involves alternation of generations
- this means that a diploid generation (the sporophyte, which produces spores) is followed by a haploid generation (the gametophyte or prothallus, which produces gametes)
- pteridophytes differ from mosses and seed plants in that both generations are independent and free-living, although the sporophyte is generally much larger and more conspicuous
- the sexuality of pteridophyte gametophytes can be classified as the following:
- dioicous: each individual gametophyte is either male (producing antheridia and hence sperm) or female (producing archegonia and hence egg cells)
- monoicous: each individual gametophyte produces both antheridia and archegonia and can function both as a male and female
- protandrous: the antheridia mature before the archegonia (male first, then female)
- protogynous: the archegonia mature before the antheridia (female first, then male)