Download Flowers, Fruits, and Seeds

Flowers, Fruits, and Seeds
Outline
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Dicots versus Monocots
Structure of Flowers
Fruits
  Fleshy
  Dry
Fruit and Seed Dispersal
Seeds
  Germination
  Longevity
Structure of Flowers
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Each flower, which begins as an embryonic
primordium that develops into a bud, occurs
as a specialized branch at the tip of a
peduncle which may have branchlets of
pedicles.
  Pedicle swells at its tip into a small pad
(receptacle).
-  Other parts of the flower are attached to
the receptacle.
Structure of Flowers
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Outermost whorl of parts that typically grows
from the receptacle is of three to five sepals.
  All together, the whorl or sepals is called the
calyx.
Next whorl consists of three to many petals. All
of the petals together are called the corolla.
  The reason you see so many different types
of flowers are because of the ways plants
modify their corollas to attract different
pollinators.
  Calyx and corolla together form the perianth.
Structure of Flowers
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After the petals, flowers have a whorl of male
parts called stamens.
  Little bags of pollen at the tips of the
stamens are called anthers. Anthers
contain sporangia. The spores produced
there develop into pollen grains containing
sperm cells.
  The slender stalks that support the anthers
are called filaments.
Structure of Flowers
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The most central
whorl of parts within
a flower consists of
female carpels–
green, vase-like
structures. In many
flowers, more than
one carpel fuses
together to form a
compound carpel,
also called a pistil.
Structure of Flowers
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Each carpel or pistil has
three parts:
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The tip of the pistil is the
stigma. Pollination occurs
when pollen grains land
on the stigma.
The long tubular part of
the pistil is called the
style. Pollen grains grow
long tubes down through
the style in order to reach
the base of the pistil.
Structure of Flowers
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The ovary (purple) contains
ovules (green). The ovules
are the female sex cells, and
when fertilized they grow
into the seeds of the plant.
The swollen base of
the pistil is the
ovary. Inside the
ovary are chambers
that contain one or
more ovules. After
the ovules are
fertilized with sperm
from the pollen, they
will develop into
seeds.
Structure of Flowers
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One way that flowers can look different from
each other is based on the position of the
ovary relative to the calyx and corolla.
  Superior Ovary - Calyx and corolla are
attached to the receptacle at the base of
the ovary.
  Inferior Ovary - Receptacle grows up and
around the ovary.
-  Calyx and corolla appear to be attached
at the top.
Structure of Flowers
Superior Ovary
Inferior Ovary
Generalized Flower
Dicots versus Monocots
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Dicots
Two cotyledons
Flower parts in fours or
fives
Leaves with distinct
vein network
Vascular cambium
present
Vascular bundles in
ring
Pollen grain with three
apertures
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Monocots
One cotyledon
Flower parts in threes
Leaves with parallel
primary veins.
Vascular cambium
absent
Vascular bundles
scattered
Pollen grain with one
aperture