lab 1: introduction to flowers + clove, for second year pharmacy students, Al-Azhar University by Dr Mahmoud Sallam demonstrator at pharmacognosy department.

1. Lab. 1: Introduction + Clove
By: Dr. Mahmoud Sallam
Demonstrator at faculty of pharmacy , Al-Azhar University.
Flowers
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2. Dr. Mahmoud Sallam

3. The Flower ( the reproductive part of the flowering plant )
 Definition:
 The flower is a modified shoot to be suitable for the process of reproduction.
 The stem to be contracted and the leaves are modified into floral parts so
the sepal, petal, stamen and carpel represents modified leaves.
 Highly specialized for the performance of reproductive function and adopted
to produce seeds and fruits → propagation of the individuals.
 Function:
 Floral characteristics are the most commonly features to identify
plants ( Much more reliable than vegetative characteristics ).
Dr. Mahmoud Sallam

4. Flower parts
Dr. Mahmoud Sallam

5. Flower parts
Sepals
Formerly protected the flower bud
Petals
Attract insects and
other pollinators
Stamens
(Androecium)
Pollen-producing part
Pistil
(Carpels, Gynaecium)
Ovule-producing part
1- Anther: makes pollens
2- Filament: support
1- Stigma: traps pollen
2- Style: pollen tube
travels through it.
3- Ovary: contain egg cells
Receptacle
Pedicel
Dr. Mahmoud Sallam

6. TYPICAL PARTS OF FLOWER:
 A typical flower is formed of FOUR SETS of floral leaves:
II. Essential (fertile) parts:
3. Stamens (♂):
- Male reproductive structures
- (Anther + Filaments)
- All stamens called androecium
4. Carpels (♀):
- Male reproductive structures
- (Stigma + Style + Ovary)
- All carpels called the gynaecium
 These parts are arranged on a shortened axis (Flower Stalk, Rachis, Pedicel)
the expanded apex of which is called the Receptacle.
I. Non-essential (sterile) parts:
1. Sepals:
- protect flower bud
- All sepals called calyx.
2. Petals:
- pretty parts that attract pollinators
- All petals called corolla
• Calyx and corolla make up the perianth

7. Some important terms:
 when the outer floral leaves (sepals & petals) are similar (
nearly indistinguishable).
- Then the individual parts are referred to as tepals.
- E.g. family Liliaceae
Perianth:
 A leafy structure from its axil arises a flower.
- If it is present the flower is called as bracteate.
- If it is absent then the flower is called as ebracteate.
Bract:
 A bract-like structure present on the pedicel between the
bract and the flower.
 These are small and thin than the bract and may be one
or two in number.
- If they are present the flower is called bracteolate.
- if absent then the flower is called as ebracteolate.
Bracteole:
 A group of bracts arranged in one or more whorls just
below the flower.
 E.g. family Compositae.
Involucre:
Dr. Mahmoud Sallam

8. Terms Applied to Individual Flowers
 Have all 4 floral parts (sepals, petals, pistil & stamen).Complete flower:
 Missing one or more of the floral parts.Incomplete flower:
= Hermaphrodite, Bisexual.
 When both androecium & gynaecium are present.
 E.g. Clove.
Perfect flower:
 Missing stamens or carpels, but not both.
o Unisexual = when only one of the sexual organs
is present.
1. Staminate: male flower.
2. Pistillate: female flower.
o Sterile = when both of the sexual organs are
absent.
Imperfect flower:
Terms Applied to Plants with Imperfect Flowers
 Both staminate & pistillate flowers are present on the
same plant.
Monoecious plant:
 Staminate flowers on one plant and pistillate flowers
on a different plant.
Dioecious plant:
Presence or Absence of Parts

9. Monoecious plant:
Arrowhead male Arrowhead femaleDr. Mahmoud Sallam

10. Dioecious plant:

11. 1- Calyx (sepals)
 The outer whorl of the floral leaves.
 One of the non-essential organs of the flower.
 Usually green in color.
Definition:
 Protection of the essential organs of the flower.Function:
 The calyx is formed of 2 to 5 sepals, and may be:
1. Polysepalous (free): each sepal is separately attached
to the receptacle.
2. Gamosepalous (united): sepals are completely united
through their margins.
Cohesion:
 Tubular, Campanulate .. Etc.Forms:

12. Polysepalous

13. Tubular calyx Campanulate calyx

14.  The inner whorl of the floral leaves.
 One of the non-essential organs of the flower.
 Usually colored.
Definition:
 Pretty parts that attract pollinators
 Protection of the essential organs of the flower.
Function:
 Corolla may be:
1. Polypetalous: with free petals.
2. Gamopetalous: with united petals.
Cohesion:
 Tubular , slaver-form, Funnel-form, Camanulate, Legulate,
Bilabiate, cruciform, spurred, Urceolate (urn-shape).
Forms:
2- Corolla (Petals)
Dr. Mahmoud Sallam

15. Flattened strap-shaped
extension of petal

16. Narrowed at the openingBell-shaped Cross-shaped

17. Backward or downward
extension of petal
widens gradually from
base to tip
Two-lipped

18.  One of the essential organs of the flower
 Formed of stamens arranged within or above the corolla
Definition:
 The stamen consists of:
1. Anther:
• Swollen pollen-producing part.
• It is divided into 2 anther-lobes. Each anther-lobe
includes 2 elongated pollen-sacs containing pollen
grains.
2. Filament:
• Slender stalk which bears the anther.
Structure:
• Staminode stamens: sterile (i.e. not producing pollen grains).
• Sessile stamens: Filaments are absent.
3- Androecium (Stamens)

19. Types of Androecium
 According to the length of filaments:
1. Didynamous: formed of two long and two short stamens
- e.g. Labiatae.
2. Tetradynamous: formed of four long and two short stamens
- e.g. Cruciferae
 According to fusion of the filaments together with free anthers are:
a) Monodelphous: (when filaments are fused in one group).
b) Didelphous: (when filaments are fused in two groups).
c) Tri, Tetra- and Polydelphous: (when filaments are fused in three, four
or more groups).
 N.B. Syngenesious anther (the filaments are free but the anthers are uni
ted e.g. Compositae).
Dr. Mahmoud Sallam

20. A and B, diagram and
sector of t.s. of young
anther.
p, pollen sac, cn, connective tissue, v.b. vascular bundle; ep, epidermis ;
f, fibrous layer; ml, middle layers; t, tapetum; pl., pollen grain
C, and D, diagram and
sector of t.s. of a ripe
anther.
The structure of the anther

21. Pollen grains:
 They are formed from pollen-mother cell, occurring in pollen-sac.
 Structure: Pollen grains consists of a wall of two membranes:
1. Intine: a inner delicate cellulosic membrane.
2. Exine: an outer thick cutinized wall.
 The exine may be: smooth (saffron), warty (Santonica), pitted
(Hyoscyamus), spiny (Chamomile), triangular (clove) or
hexagonal (Lavender).
 The exine may show:
o Germ pores: one, two, and commonly three or more
minute thin area from which the pollen-tube produces.
o Germinal furrows: narrow lanceolate areas or grooves,
in the center of each furrow the germ pore is situated.
Exine
Intine

23. 4- Gynoecium (Pistils, carpels)
 One of the essential organs of the flower
 consists of one, two or more carpels and according to their
number the gynaecium is described as:
1. Monocarpellary [one],
2. Bicarpellary [two],
3. Multicarpellary [More].
Definition:
 Apocarpous (free carpels).
 Syncarpous (united carpels).
cohesion:

24. The ovary
 The ovary my be simple, formed of one carpel or compound formed of
two or more carpels united together.
 Carpels may form one compartment (i.e. Unilocular) or two (Bilocular),
three (Trilocular) or more (Multilocular).

25. The placenta
• Usually formed of the swelling of the cohering margins of the carpels.
• Its number is usually indicate the number of carpels forming the gynaecium.
• It may be:
1. Marginal: Ovules arranged on fused margins of the carpel.
2. Parietal: Ovules arranged on fused margins of unilocular
compound ovary.
3. Axile or Central: Ovules are arranged on the central axis of
multilocular ovary.
4. Basal and Apical: One ovule attached at the base or apex of
unilocular ovary.
Dr. Mahmoud Sallam

26. Insertion of Floral Parts
Hypogynous
- Sepals, petals, and stamens are inserted
under the ovary.
Ovary is said to be superior
Perigynous
- Sepals, petals, and stamens are inserted
on the edge of receptacle which surrounds
the ovary but not fuse with it).
Ovary is said to be superior
Epigynous
- Sepals, petals, and stamens are inserted
on the receptacle which has fused with and
closed over the ovary
Ovary is said to be inferior

27. INFLORESCENCES

28.  Umbel
with very short axis from which pedicels of nearly equal lengths and radiating,
thus forming an umbrella-like structure.

29.  Capitulum Or flower head
with very short axis which swollen into a conical structure and on which are
inserted sessile flowers (the axis is wrongly known as receptacle) usually there
are two types of small flowers called florets, one have tubular corolla called
disc floret and the other strap- like called ray floret.
Dr. Mahmoud Sallam

31. Mizzotti et al.

32. Cloves ‫القرنفل‬
 Origin: Dried flower buds of Eugenia aromatica,
Syzygium aromaticum or
Eugenia caryophyllus, family: Myrtaceae.

33.  Description:
a) Morphology: bright reddish-brown to dark
brown show the following:
1) Hypanthium (Elongated part Lower part):
It is solid, cylindrical, 4-sided, showing
a central zone called columella
surrounded by dark lacunous layer.
2) Calyx: 4 thick divergent, triangular sepals.
3) Corolla (spherical head): 4 rounded,
unexpanded, form dome-shaped petals
alternated with the sepals, enclosing
numerous stamens
4) Stamens: Indefinite, Curved inwards, the
filaments are united in 4 groups
(i.e. Tetradelphous).
5) Gynaecium: Consists of a stiff slender style
and two-celled bilocular inferior ovary with
numerous ovules attached to axial placenta.

34. b) Histology: The T.S of hypanthium shows the following layers:
1) Epidermis: Formed of small, thick-walled cells with thick cuticles
and anomocytic stomata.
2) Parenchymatous layer: Containing numerous large oval schizo-
lysigenous oil gland.
3) Collenchymatous parenchyma layer: Containing cluster crystals of
ca-ox and traversed by vascular bundles (xylem, phloem and
pericycle shows thick-walled pericyclic fibres.
4) Lacunous layer: Formed of parenchyma
5) Columella layer: Formed of parenchyma with numerous cluster of
ca-ox and vascular bundles.
N.B. In the ovary region there is no
lacunous or columella layers, where
their situation is replaced by bilocular
ovary with cluster crystal of ca-ox.
T.S. in ovary region
T.S. below the ovary

35.  Schizo-lysogenous Oil gland:
Secretory cavities or sac arise by separation of the cells and subsequent formation
a secretory epithelium (schizogenously) or by breakdown of the cells forming a
cavity not bounded by a definite epithelium (lysigenously).

36.  Powder:
o Dark brown, with strong characteristic aromatic
odor and pungent spicy taste followed by slight
numbness.
o It characterized by:
1. Fragment of epidermis with thick straight
anticlinal walls and few anomocytic stomata.
2. Fragment of parenchyma and collenchyma
with cluster crystals of ca-ox.
3. Numerous triangular pollen grains.
4. Fragment of fibrous layer of the anther.
5. Fragments of filament showing oil glands,
cluster crystals of ca-ox.
6. Numerous oil glands stain red with Sudan III.
7. Fragments of spiral vessels and lignified fibres
.

37.  Active Constituents:
1. 15-20% Volatile oil, containing:
• Eugenol (90%),
• Acetyl Eugenol (3%),
• , , -Caryophyllenes (8.5%), Clovene, Isoclovene.
2. Tannins (Gallotannic acid, 13%).
 Uses:
 Aromatic stimulant.
 Antispasmodic, Carminative, Spice.
 Toothache, Antiseptic.
 Preparation of Vanillin.
 Adultrants:
– Clove Stalk.
– Mother Cloves.
– Exhausted cloves.

39. That’s it, Thank you