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Fern development at the example of a dot fern

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frond of a dot fern
Frond of a dot fern
Prothallus dies and a young fern grows up.
new frond

Above
1. Generation:
Fern fronds, you can see in the forests.

sori at the back of a dot fern
Each dot at the frond underside contains a group of spore cases (sori)

Antherozooids free swimming and one fertilizes archegonium.

egg cell and sperm cell of a fern
Sporangia under the microscope
open Sporanga from Asplenium hemionitis
Sporangium from Pyrrosia
Sori from genus Hemionitis
sporangia with spore
Sporangium shedding spores
Under surface of a prothallus. Archegonia above, antheridia below at the prothallus.
prothallus back
Left
2. Generation: Prothallus, looks like a leef 0,5 to 1cm in diameter.
spores
Spores
Spores develop into a prothallus
prothallus with spore
The 2 gernerations of fern plants

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Different fern species have differnt sori

Photos to increase click

Sorus
Sorus
Sori
Sori covered with hairy indusia
Sori
Sorus
Polipodium sori are roundish and lack indusia
Spores in cover in the form of pea with Psilotum nudum
Polystichum setiferum, sporangia covered with roundish indusium

Hairy indusia with
Microgramma

Blechnum cordatum, sporangium under rolled up border
Pilularia sporecases like a little hairy pill

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Explanation of the used terms
group of spore cases sori
spore cases sporangia
prothallus gametophyte
genital organs gametangia
feminine sex organ archegonia
male sex organ antheridia
familiar fern plant sporophyt