Transcript Phylum Pterophyta - Miss Stanley Cyber Classroom

Phylum Pterophyta
Vascular Plants Without Seeds
Ferns
Ferns:
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nonflowering vascular plants
Spore-bearing leaves
Horizontal
undergound stems
1-2 feet tall
Tropical ferns may
grow as tall as 60 ft.
with fronds 12-14 ft.
Some are epiphytes
Parts of a fern:
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Fronds – leaves
Rhizome – a creeping
or underground stem,
which produce roots
Sori – groups of
spore-bearing
sporangia (means “a
heap”)
Fern Sori
Sporophyte Generation of Ferns
A new fern’s life cycle
typically begins in July
with the appearance of
sori on the undersurface
or along the margins of
a frond.
Sori may be round, kidney-shaped, oblong, linear,
curved or star-shaped.
Sporophyte Generation
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Sori appear on the
underside of a
frond.
Sori first open and
discharge millions
of spores.
Gametophyte Generation
Spore develops into
a tiny green, heartshaped structure
called a prothallus.
Seldom seen, only 1 cell
layer in thickness.
Gametophyte Generation
The underside of the prothallus develops archegonia and antheridia
Antheridia near the point
(sperm)
Archegonia at notched end
(ova)
Gametophyte Generation
Sperm are released
from the antheridia
and swim to the
ovum at the bottom
of the archegonia.
Sporophyte Generation
Zygote matures and sends the first
leaf up and the first root down.
The first leaf is often a fan-shaped
blade.
The second leaf is usually a
fiddlehead, a coiled young leaf.
Some fiddleheads are edible and
used in salads.
Fern Alternation of Generation Facts
Ferns usually require 3-7 years
to reach reproductive maturity.
Fern plants (sporophytes) live for
several years and produce new
fronds each year
Dominant generation:
Sporophyte
Protellia (gametophytes) only live
3-7 weeks, in which time they
produce the archegonia and
antheridia.