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The Parts of a Flower
Competency
1. Identify the parts of the flower
and its function- addendum
Activity: Simple Recall Q & A
•What are flowers for?
•What are the parts of the flower that you know and give
its function
•Is there a male and female part of the flower?
•How do flowers pollinate or fertilize?
Video presentation:
Reproductive Cycle of a flower
www/youtube.flowerreproductive.com/skk/lkk
Why a Flower?
FLOWER – branch of stem bearing leaves specialized to carry reproduction.
Largest – Corpse Lily
The corpse lily (Rafllesia arnoldii) is a parasitic
plant that grows inside a vine in the grape
family. It has no leaves or stems. A mature
flower measures up to three feet across and
weighs 15 to 25 pounds. Found in the rainforest
or Borneo
. The smallest individual flowering
plant is watermeal, a member of the
duckweed family. The plant itself is
1/32 of an inch in width, or about
the size of a pinhead. Found in the
freshwaters of Austria
Parts:
1. Floral Stalk/Twig:
1.Peduncle –floral axis – stalk of floral cluster
2.Pedicel – stalk of individual flowers
3.Receptacle – tonus or thalamus – enlarged tip of floral twig.
2. Perianth/Floral Envelope
•sepal – calyx – outermost whorl
•petals – corolla – colored inner whorl
parts: lamina and claw
Petal: Corolla
Sepal:Calyx
Calyx: the outer whorl or sepals;
typically these are green, but are
petal-like in some species.
Corolla: the whorl of
petals, which are usually
thin, soft and colored to
attract animals that help
the process of pollination.
The coloration may
extend into the ultraviolet,
which is visible to the
compound eyes of insects,
but not to the eyes of
birds.
3. Essentials Parts:
A. Stamen – androecium – male reproductive
1.anther – box like pollen sacs
2.filament – stalk
Male Parts and Functions
• Stamen – is the male reproductive part of a
flower.
• Anther – produces pollen grains which
develop sperm.
• Filament – supports the Anther.
Flower Anatomy
Androecium (from Greek
andros oikia: man's house):
one or more stamens, each
with a filament topped by an
anther where pollen is
produced.
Pollen contains the male
gametes.
2.Pistil – gynoecium – female reproductive organ
a.ovary – enlarged basal tip
b. style – stalk arising at the ovary
c. stigma – tip of the style
Female Parts and Functions
• Pistil – is the female reproductive part of a
flower.
• Stigma – sticky pollen-receptive part of the
pistil.
• Style – the stalk of the pistil down which the
pollen tube grows.
• Ovary – contains the ovules and becomes the
fruit.
• Ovule – becomes the seeds when sperm cells
fertilize the egg cells.
Flower Anatomy
Gynoecium (from Greek gynaikos oikia: woman's
house): all the female parts—the pistil(s) with
ovule(s) inside.
Flower Anatomy
The basic unit of the female reproductive
structure is the carpel. Each physcial body is
called a pistil.
A flower may have a single carpel, which is a
simple pistil (unicarpellate), or several carpels
united in one compound pistil (syncarpous), or
a cluster of un-united carpels/pistils
(apocarpous)
The sticky tip of the pistil, the stigma, is the
receptor of pollen.
The supportive stalk, the style, becomes the
pathway for pollen tubes to grow from pollen
grains adhering to the stigma, to the ovules,
containing the gametes, housed inside the
ovary.
Flower Anatomy
carpel
fertilization
carpel structure
Flower Structure Variation
perfect
imperfect
imperfect
Flower Structure Variation
Ovary Position
A. ovary superior, floral parts hypogynous
B. ovary inferior, floral parts epigynous
C. ovary half-inferior
D. ovary superior, floral parts perigynous, hypanthium cup shaped
Flower Structure Variation
A flower having sepals, petals, stamens, and pistils is
complete; if a flower is lacking one or more of these
whorls, it is said to be incomplete.
complete
incomplete
no stamens present = incomplete
Inflorescences
An inflorescence is a group or cluster of flowers. It
may be branched or unbranched. Modifications can
involve the length, variations in the proportions,
compressions, and swellings, and the order in which
the flowers open.
Usually the modifications have been evolved to
optimize the plant’s method of pollen dispersal.
Inflorescences
raceme
spike
corymb
umbel
Inflorescences
spadix
head
catkin
Pollination
• Pollination is the process in which pollen is
transferred in the reproduction of plants.
Cross-pollination
Is when pollen is delivered to a
flower from a different plant.
Self-pollination
Is when pollen from one flower
pollinates the same flower of the
same plant.
• Some methods of pollination
–
–
–
–
Animals (birds, reptiles, mammals)
Insects (bees and butterflies mostly)
Wind
WATER
Steps to Flower/Plant Reproduction
***Reproduction of a plant takes place in the flower***
Pollination
• 1. The Anther produces pollen
• 2. That pollen is transferred to the stigma of itself or
another flower through pollination.
Fertilization
• 3. Pollen travels down the style to the ovary to
fertilize the eggs.
• The eggs grow into a seed or seeds and can now
reproduce.
Pollen Dispersal by Animals
Bees, Beetles, Bats, Birds, Butterflies, etc…
What controls flowering?????
• The length of Night!
1. During the day plants taken in
light, water and nutrients needed to
go through photosynthesis.
2. Then at night it uses the glucose
(food) to grow and
reproduce…FLOWER.
Symmetry
Flowers that are actinomorphic have
"radial symmetry", meaning they can be
divided into symmetrical halves by more
than one longitudinal plane passing through
the axis, much as a pie can be cut into
several equal and identical pieces.
Zygomorphic flowers are "yoke shaped”
or have"bilateral” symmetry, where
flowers can be divided by only a single
plane into two mirror-image halves, much
like a yoke or a person's face.
Dicot versus Monocot
Dicot
Monocot
Lab Objectives
1. Flowers are arranged in groups called inflorescences. We will examine some
inflorescences particular to certain families later in the semester. For now,
know what an inflorescence is and which ones we looked at today.
2. DRAW a longitudinal section of a typical flower labeling the following parts:
receptacle, calyx, sepals, corolla, petals, perianth, pedicel, ovary, ovule, style,
stigma, pistil, gynoecium, anther, filament, stamen, and androecium.
3. EXAMINE by dissection the floral material provided making long and cross
sections of the flower and its parts. On a separate sheet of paper, SKETCH the
flowers and label the parts. Then, FOR EACH FLOWER, answer the following
questions:
A. Is the flower actinomorphic (regular) or zygomorphic (irregular)?
B. How many sepals are present? Petals? Stamens? Carpels? To count carpels,
count the locules, styles, style branches, and/or the zones of placentation by
cross- sectioning the ovary.
C. Is the ovary inferior or superior?
D. Is the flower from a monocotyledonous or dicotyledonous plant?
E. Is the flower perfect (both sexes present) or imperfect? Complete (all four
floral whorls) or incomplete?