Ferns are a group of plants adapted to live on land. The dominant generation in ferns is the sporophyte generation, which represents the adult fern plant with true roots, an underground stem, and large compound leaves. Spores are produced in clusters called sori on the underside of leaves and are dispersed by wind. When spores germinate, they produce a small heart-shaped gametophyte generation that bears male and female sex organs requiring water for fertilization to occur and form a new sporophyte fern plant.

1. PTERIDOPHYTES - FERNS
► Pteridophytes are a group of plants that are adapted to live on land.
► Ferns mostly occur in moist , shady environments.
► Unlike the Bryophytes , the sporophyte generation is the dominant
generation in ferns.
► The adult fern plant represents the sporophyte generation
► The fern has true roots , stems and leaves. i.e. it is not a thallus.
► In most ferns (excluding tree ferns) the stem is a horizontal , underground
rhizome
► Adventitious roots develop from the rhizome, anchor the plants in the soil
and absorb water and mineral salts.
► The green compound leaves (fronds) with long leaf stalks develop from buds
on the rhizome
► Well-developed vascular tissue (xylem and phloem) is present.

3. structure – continued.
► The sporophyte is perennial and therefore produces spores over many
generations
► Clusters of sporangia are found on the underside of leaves.
► These clusters of sporangia are called sori (singular : sorus)
► spores are released from the sporangia and dispersed by the wind.
► When a spore germinates, it gives rise to a green, heart-shaped prothallus,
that represents the gametophyte generation.

4. FERNS
• the gametophyte
generation is less
prominent , has a
shorter lifespan and
disappears after one
cycle of gamete
formation and
fertilisation.

5. ferns structure continued
► Rhizoids on the ventral (lower) surface of the prothallus anchor it in
the soil.
► Male and female sex organs , which produce sperm and ova
respectively , are also found on the ventral surface of the prothallus.
► Released sperm need water to move to the ovum in the female sex
organ
► Fertilisation is dependent on water
► After fertilisation occurs, a zygote is formed and this gives rise to
the new fern plant (sporophyte).
► Initially, the young sporophyte lives parasitically on the
gametophyte. When the young sporophyte is independent (absorbs
its own water and mineral salts and can photosynthesise), the
prothallus disappears.
https://www.youtube.com/watch?v=avK7hGnaRAY
(Video is 18 minutes long. Please watch at your leisure)

7. OVERVIEW
PTERI
DOPH
YTES
Structure
of
dominant
generatio
n
(Sporoph
yte )
Vascula
r tissue
Spor
es/se
eds
Fruit
Depend
ency
on
water
for
reprod
uction
ferns True roots,
underground
stem, large
compound
leaves
Xylem and
phloem
present
spores none Water is
needed for
fertilisation