Cognosy 1
Team
Lecture 1
Clinical 2020
CAIRO UNIVERSITY
2014/2015
Before we start we like to know that our course will be about
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Flower  ( e.g. Karkadeh )
Bract  ( e.g. Cinnamon )
Wood
Herbs  ( e.g. Menta)
Definition of Flower: a modified fertile shoot carrying modified leaves adapted for reproduction.
- Consists of
Calyx
Corolla,
Androecium
Gynoecium
- Carried on a receptacle: swollen apex of flower stalk
- Bract: Is a leafy structure from the axil of which arise the flowers.
- Involucre: group of bracts arranged in one or more whorls surrounding the inflorescence
inflorescence: group of flowers
Note: Involucre is the modification of bract
- Receptacle: swollen or expanded apex of flower below calyx & ovary.
- Hypanthium: is an elongated receptacle below the Calyx & Ovary ( e.g.: clove)
Floral
leaves
Asexual
Sexual
(essential)
( non-essential)
Calyx
Corolla
Androecium
Filament
Anther
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Gynoecium
Ovary
Style
Stigma
Kinds of flowers
According to arrangement of floral leaves on the floral axis
Cyclic
the floral parts are arranged in definite whorls
around the axis of the flower e.g.: clove
Acyclic
floral parts are arranged in spirals and not in
whorls
According to the symmetry of all floral parts
Regular
Irregular
Segments are alike , regularly arranged
Segments are not alike,( irregular)
Actinomorphic
Segments could be divided into equal halves by
longitudinal cuts
Asymmetric
Segments could not be
divided into equal
halves(segments are
irregularly arranged)
Zygomorphic
Could be divided into
equal halves in only
one plane
e.g.: ray floret in
Asteraceae
According to the presence or absence of sexual organs
Complete (perfect)
Incomplete (imperfect)
Calyx , corolla ,
androecium, gynoecium
(Hermaphrodite )
Lacking calyx or corolla
Unisexual
Neutral
Either Androecium or
Gynoecium
Pistillate
Staminate
Neither
androecium nor
gynoecium
Only
Gynoecium
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Only
Androeciu
Plants of Flowers
Monoecious
Dioecious
- 1 house
Both male and female flowers
on the same plant
- 2 houses
Male and female on separate
plants
e.g.: palms
Polygamous
Both male and female
(hermaphrodite) on the same
plant
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Perianth : is the outer non-essential floral parts when they are not differentiated into calyx and
corolla (all the segments are alike )
It may be:
Sepaloid: green in color
Petaloid: colored
 Calyx
Is the outermost whorl of floral parts that protects the essential organs
Cohesion of Sepals
Polyseoalous
Aposepalous (free sepals) as in cruciferae
Gamosepalous
Synsepalous (united sepals) as in solanaceae
Pappus
Rudimentary modified calyx represented by bristles ‫ شعيرات‬instead of sepals.
Bristles:
Are hard, rough hairs
Each bristle consists of 4-5 cells in diameter one cell at the apex
e.g.: Arnica (30 bristles forming the pappus)
Epicalyx
Stipules of stipulate calyx fuse in pairs between the sepals producing an outer serious of small
sepal like structure.
e.g.: family Rosaceae
OR: Bracts, bracteoles aggregated beneath the calyx forming the epicalyx.
e.g.: Karkade ( family Malvaceae )
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 Corolla
Inner whorl of the floral parts which attract the pollen carrying insect, also protect the essential
organs
Cohesion of petals
Polypetalous
Gamopetalous
Apopetalous (free petals) e.g.: Rosaceae
Sympetalous (united petals) e.g.: Solanaceae
Insertion of corolla
Hypogenous
Perigenous
When inserted on receptacle
below the ovary as in Rutaceae
e.g.: lavender
When inserted on the edge of
hollow receptacle surrounding
the ovary but does not fuse
with it
Epigenous
When inserted on receptacle
above the ovary
e.g.: clove
 Androecium
 Anther
-Divided into 2 anther lobes by connective tissue
-Each anther lobe possesses 2 pollen sacs, containing pollen grains.
 Filament
-Bears (carries) the anther
Description of stamens
1- Equal length (usually)
2- Unequal length
Didynamous
Tetradynamous
2 long & 2 short stamens
4 long, 2 short stamens
e.g.: labiateae
e.g.: cruciferae
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Staminode stamens: Sterile stamens.( don't produce pollen grains).
 Cohesion of stamens: (free or united → by filaments-or by anthers):
Fused by filaments
- Monodelphous: filaments fused in one group
- Diadelphous: filaments fused in two groups
- Tetradelphous: filaments fused in four groups e.g.: clove
- Polyadelphous: filaments fused in several groups
Fused by anthers
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Syngenesious: filaments free, anthers united e.g.: Asteraceae  (as: chamomile)
-Adhesion of stamens
• Epipetalous adhesion between stamens and petals
(stamens appear inserted upon corolla or partly fused with it)
Attachment of anther
Manner of attachment of anther to filament
1- Basifixed ( innate) : attachment by base of the anther
2- Dorsifixed : attachment by back of the anther, immovable
3- Versatile : attachment by back of the anther , movable
(attached by the middle of its back so move freely)
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Pollen grain structure
1- Exine: thick cut inized
2- Intile: thin, cellulosic
Germ pores: minute pits for protrusion pollen tubes
Germ furrows: grooves [exine is thinner] accommodate the expansion, shrinkage of pollen grain
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Gynoecium: is the female sexual organ.
Pistil ( Gynoecium) = carpel
-Stigma: apical portion shows papillae to receive pollen grain.
-Style: connect the stigma with the ovary
place stigma in suitable position to receive pollen grains
-Ovary: enclosing ovules on its margin.(placenta which is thickened cohering margins of the
carpel)
Style
Present
stalked stigma
Absent
Sessile stigma
Gynobasic
Terminal
Lateral
Near the ovary
on the top of ovary
on side of the ovary
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Composition of the ovary
Compound
Simple
 Monocarpellary
 one carpel
Bicarpellary & Polycarpellary
more than one carpel
Apocarpous
Free carpels
Syncarpous
United carpels
Fusion of Caprels (Syncarpous Ovary)
Complete
 Caprels are united(compound)
Styles fused in one
Stigmas formed undivided structure
partial
 Caprels are united only at the base
Styles free
Stigmas corresponding to the number of carpel
Insertion of Ovary
Superior
Inferior
Floral parts are inserted on the receptacle
below the ovary or on the same level
Floral parts are inserted on the receptacle
above the ovary ( on its top )
Placentation
describes the
postion of placenta
in the ovary
One
Ovule
Basal
Numerous
Ovules
Apical
Marginal
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Parietal
Axile
Central
One Ovule
Basal
Apical
one single ovule
carried on
Placenta arising
on centre of the
ovary base
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One single
ovule carried
on Placenta
arising from
apical part of
Ovary
Numerous Ovules
Parietal
Axile
Marginal
Central
Monocarpellary Multicarpellary Multicarpellary Multicarpellary
Unilocular
, Unilocular
Bi unilocular
ovary
ovary
multilocular
ovary
ovary
Placenta
develops along
the junction of
the two
margins
Placenta
develops along Margins of
the junction of carpels
the carpels
fuse forming a
central axis
Arrangement of flower on the Plant
Central axis
arising from
ovary
base , not
attached to
ovary
wall
Solitary
Aggregated  Inflorescence
Inflorescence : the aggregation of flwers on the plant its axis is called Rachis
Inflorescence
Racemose
Cymose
Growing point has an indefinite
power of growth
growth of the main axis is
limited by a flower
Elongated rachis
Elongated rachis
Shortened rachis
Shortened rachis
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Mixed
Both types of branching present on
the same inflorescence
The main axis bears racemose
inflorescence , lateral axes bear
cymose inflorescence
e.g. Family Lamiaceae
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