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aquatic ferns
I came across an interesting website:
http://www.visuallink.net/fern/lernfrnl.htm where I learned some very
interesting facts! Aquatic ferns were apparently the evolutionary
precursors of terrestrial ferns from which all terrestrial plants are
descended! There is also a family tree and I could recognize many of our
familiar aquarium plants including the Isoetes family, Marsilea, and
Salvinia not to mention Java fern, Bolbitus and the mosses.
Another interesting fact about ferns is that during the gametophyte
stage of sexual reproduction, there are spermatozoids which actually
swim to the egg organ, the Archegonium, to fertilize it. This fertilized
egg then grows into the mature fern plant as we know it. The gametophyte
itself is only a precursor form! The evolution of sex!!
The figure 4 Life cycles of ferns was a bit mysterious. What are these
references to melotic nuclear division and melospores and mitospores?
What are Apogamous outgrowths?
--
Steve Pushak Vancouver, BC, CANADA
Visit "Steve's Aquatic Page" http://home.infinet.net/teban/
for LOTS of pics, tips and links for aquatic gardening!!!