DEPARTMENT OF GENETICS AND PLANT BREEDING
ALLAHABAD SCHOOL OF AGRICULTURE
SAM HIGGINBOTTOM INSTITUTE OF AGRICULTURE TECHNOLOGYAND SCIENCES
(Formerly Allahabad Agricultural Institute)
DEEMED TO BE UNIVERSITY
Allahabad- India -211007
M.Sc Ag SST
Dr . SHAILESH MARKER
Head of department,
Dept. of Genetics and plant
Topic: floral structure
Introduction to floral structure
Flower parts and their functions
Classification of flowers
Floral formula and diagram
Floral biology of some families viz, Graminae,
leguminaceae and malvaceae
Summary and conclusion
A flower is the
found in plants.
function of a flower is
to mediate the union
of male sperm with
female ovum in order
to produce seeds.
FLOWER sits a top of a stem
Sepals from the latin sepalum
Petals from the latin petalum “to
Stamens are the pollen producing
part of a flower.
Androecium “house of man”.
Carpel from the greek word
Collectively known as
gynoecium “house of woman”.
Flower Part Form and Function
Peduncle Flower stalk.
Receptacle Part of flower stalk bearing the floral organs, at base of flower.
Sepal Leaf-like structures at flower base, protects young flower bud.
Calyx All the sepals together form the calyx.
Located in and above the sepals, often large and colourful, sometimes
scented, sometimes producing nectar. Often serve to attract pollinators
to the plant.
Corolla All the petals together form the corolla.
Male part of the flower, consisting of the anther and filament, makes
Filament The stalk of the stamen which bears the anther.
Anther The pollen bearing portion of a stamen.
Grains containing the male gametes. Immature male gametophyte
with a protective outer covering.
CarpelPistil Female part of the flower. Consisting of the stigma, style and ovary.
Often sticky top of carpel, serves as a receptive surface for pollen
The stalk of a carpel, between the stigma and the ovary, through
which the pollen tube grows.
Enlarged base of the carpel containing the ovule or ovules. The ovary
matures to become a fruit.
Located in the ovaries. Carries female gametes. Ovules become seeds
Types of Flower
Flower can vary in the type of
A flower containing all four
modified leaves is said to be
If a flower that lacks any of these
modified leaves is said to be
BASED ON SHAPE OF FLOWER
The sex of a flower can be described in three ways:
1.Staminate flowers: Flowers bearing only male sex parts. These
are sometime referred to as "male flowers".
2.CarpellatePistillate Flowers: Flowers bearing only female sex
parts. These are sometimes referred to as "female flowers".
3.HermaphhroditeComplete flowers: Flowers bearing both male
and female sex parts.
A flower is basically made
up of four concentric rings
There is an outer ring of
modified leaves called sepals.
These provide protection to
the flower before it opens and are usually green. This
outer ring is known as the calyx.
Inside the sepals is another ring of modified leaves
called petals which are often brightly coloured. This
layer is known as the corolla.
Floral Formulas and Diagrams
A floral formula is a "shorthand"
method used to represent the
structure of a flower using the
standard set of symbols shown at
The four major floral parts are always shown in the same
order; sepals (CA), petals (CO), stamens (A), and carpels
(G). The number of each part in the flower is indicated with
a superscript number after the letters.
Cereal crops are mostly grain crops belonging to the
grass family Graminae (Poaceae).
The word cereal is derived from ceres, the name of
the roman Goddess of harvest and agriculture.
The major cereal crops are Wheat, Rice, Corn,
Barley, Rye, Oat, and include the millets.
Several non grass crops grown for their grain are
Infloroscence of Rice is called Spikelet. Spikelet
consists of one fertile and two vestigial florets
represented by two glumes below the fertile floret.
Characteristics of Rice
The lemma may or may not be indurated,
entire, pointed, hairy or glabrous, strongly
carinate, awnless or mucronate or awnless.
Palea present relatively long, but shorter than lemma
Fertile floret: hermaphrodite, cleistogamous or chasmogamous
in some cases cross pollination is prevelent, calyx and
corolla(perianth) are called lodicules.
Stamens 6, anthers 2-3mm long with filaments, not penicillate,
versatile, ovary glabrous, monocarpellary, usually one ovule,
placentation basel, styles fused(basally) or free to their basaes.
Stigmas bifid, and feathery.
Characteristics of Wheat
Inflorescence: spike, the basic unit of the
inflorescence is called a spikelet, typiclly
consisting of a basaal pair of minute sterile
bracts called glumes.
One or more distichously arranged distal florets on an often zig zag
extension of the spikelet axis called the rachilla.
The average spike of common wheat contains 25-30 grains in 14-17
Androecium typically consists of 3 or occasionally 6 distinct stamens,
Gynoecium consists of a single compound pistil of 2 or sometimes 3
carpels, an equal number of styles with feathery stigmas, and a
superior ovary with one locule.
Characteristics of Maize
The corn plant is normally monoecious.
The staminate flowers is called tassel at
the top of the stalk.
The mature pistilate inflorescence is called cob(silk).
The spikelets are usually arranged in pairs, one sessile and the other
pediceled, the spikelet is completely enclosed by two firm.
There are two florets per spikelet, each floret contains 3 stamens, 2
lodicules and a rudimentary pistil.
The lemma and palea are thinner and shorter than the glumes
The single ovary in a fertile floret bears a long style are silk which is
forked at the tip.
The silk are ordinarily 10-30cm long.
GENERAL CHARACTERS OF
The flowers often have five generally fused sepals
and five free petals.
They are generally hermaphrodite, and have a short
hypanthium, usually cup shaped.
There are normally ten stamens and one elongated
superior ovary, with a curved style. They are usually
arranged in indeterminate inflorescences.
Fabaceae are typically entomophilous plants (i.e. they
are pollinated by insects), and the flowers are usually
showy to attract pollinators.
General characteristics of Redgram
Infloroscence: Terminal or axillary raceme.
Flowers: Bisexual irregular, zygomorphic,
pentamerous, yellow, red or yellow-purple with
brownish black in colour.
Calyx: Gamosepalous, four lobed, two lobes being
Corolla: Papilionaceous, standard petal auricled.
Wings and keel yellow of equal length, keel
incurved at apex.
Androecium lie within the two keel petals, nine unequal
stamens unite to make up the 10th stamen is free vexillary,
The filaments elongate in the bud and pollen is shed the day
before the flower opens.
Gynoecium: monocarpellary, superior many ovules in
marginal placentation. Ovary and base of style hairy; stigma
General characteristics of Groundnut
The flowers are bisexual,
The ovary is surrounded by the
base of the hypanthium.
Petals are orange, yellow, cream or
Wings are yellow at the base and orrange apically two brick red,
keel coloureless to faintly yellow.
There are 10 stamens, sterile filaments usually 2,
The tip of the ovary, bearing from 1-5 ovules,grows out from the
between floral bracts.
GENERAL CHARACTERISTICS OF
Usually herbaceous, sometimes trees or shrubs.
Leaves are alternate, stipulate, simple and entire.
The stamens are five to numerous, and
connate at least at their bases, but
often forming a tube around the pistils.
The pistils are composed of two to many
The ovary is superior, with axial placentation, with
capitate or lobed stigma.
The flowers have nectaries made of many tightly
packed glandular hairs, usually positioned on the sepals.
Flower morphology, continued
Stamens numerous, filaments connate
into a tube for most of their length.
Carpels (1) 2-many, either loosely
coherent in a ring around the base
of the single style or wholly united in a compound ovary.
Style with as many long or short branches as there are
Ovules 1-many per carpel.
Summary and conclusion
Summary: By studying the flower structure of the field
crops we came to know about its floral biology, floral
morphology and pollination mechanism to take up the
Conclusion: As a part of Seed Technologist or plant
breeder it is necessary to know about the floral biology,
morphology and pollination mechanism to maintain the
genetic purity, isolation distance and germplasm etc.