This document provides information on the leaf structure and morphology of plants. It defines a leaf and describes leaf characteristics such as shape, size, texture, venation, and margin. It discusses leaf types including simple, compound, and modified leaves. The internal structure of leaves is examined including the epidermis, mesophyll, vascular tissue, and trichomes. Stomata types and distribution are covered. Specific leaf details are given for Digitalis purpurea and Digitalis lanata, medicinal plants used for their cardiac glycoside content.
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All leaf
2. The Leaf
(Latin: Folium)
• a lateral outgrowth or an appendage on the stem.
• possesses neither nodes nor internodes and buds
or lateral branches arise in its axil.
• Characters:
• - flattened form
• - thin texture
• - presence of chlorophyll
• - presence of veins
4. 1- Cotyledons (Seed leaves). 2-Foliage leaves (green
ordinary leaves)
3-Bracts 4-Modified Leaves
Needles and Spines
Two Seed Leaves
and One Tiny True
Leaf
Types of leaves
Tendrils
5. Phyllotaxis
• It is the disposition of the leaves on the stem.
• The leaves being arranged on the stem in a
definite manner characteristic for each species
of plants.
11. Forms of Compound leaves
Paripinnate Imparipinnate Palmate
Ternate Bipinnate
12. General description of the lamina of a
simple leaf
• general outline or shape
• Size
• Apex
• Base
• Margin
• Venation
• Surface
• texture
13. General outline or shape
• a- when the lamina has nearly the same width:
Filiform
(Fennel)
Acicular
(Pinus)
Tubular
(Onion)
Linear
(Grasses)
Oblong
(Cassia)
14. • b- when the lamina has the widest portion near the base:
Continued: General outline or shape
Lanceolate
(Long Buchu)
Ovate
(Boldo) Ensiform
(Eucaluptus)
Cordate
(Ipomea)
Sagitate
(Rumex)
Hastate
(Convolvulus)
Reniform
(Asarum)
15. Continued: General outline or shape
• c- when the lamina has the widest portion near the apex:
Obcordate
(Oxalis)
Obovate
(Dog Senna)
Spathulate
(Uva Ursi )
Lyrate
( Brassica)
16. Continued: General outline or shape
• d- when the lamina is symmetric or round:
Orbicular
(Nymphea)
Elliptical
(Pear)
Oval
(Boldo)
17. Size of the leaf
• the length from the base to the apex and the
broadest width
• it varies from tiny leaves (few millimeters) as
Savin to a very considerable size as banana
• In leaves used in medicine the doesn’t exceed
about 30 cm long as Digitalis
• Leaves vary in size on the same plant being bigger
at the base and becoming smaller as getting near
the apex
18. Apex of the leaf
Acute
(Hyoscyamus)
Acuminate
( Stramonium)
Obtuse
(Oval Buchu)
Recurved
(Short Buchu)
19. Margin of the leaf
Entire
(Senna)
Revolute
(Uva-Ursi)
Dentate
Serrate
(Peppermint)
Spiny
26. Epidermis:
• mainly a protective layer
• It occurs on the surface of plants and it is a complex tissue
consisting of epidermal cells, trichomes (hairs) and stomata
• Epidermal cells:
• It consists of a single layer of cells, but in some cases it may become
many layered as a result of division
• many layered epidermis often acts as water storage tissue and the
inner layer is often described as hypodermis
• tubular or lenticular with complete absence of intercellular spaces
except where the stomata occur
27. • appear in surface view polygonal:
- approximately isodiameteric in Dicots
- axially elongated in Monocots
Leaf epidermis in Dicots
(suface view)
Leaf epidermis in Monocots
(suface view)
28. • The anticlinal walls perpendicular to the surface:
- straight as Senna, Coca
- wavy as Belladonna
- beaded due to unequal thickening or thickenings
as Digitalis
• The epidermis outer walls are:
- convex
- cellulosic
- mostly thickened
- covered with cuticle
cuticle
epidermis
29. • Cuticle varies in thickness
- thin in shady plants as Digitalis
- thick in sunny regions plants
as Uva Ursi
Thin epidermal cuticle Thick epidermal cuticle
30. • Cuticle may be:
- smooth as Stramonium
- finely ridged appearing in surface view
striated as Belladonna
- formed mainly of cutin which is an aggregate
of modified fatty acids, partly combined with alcohols
• Epidermal cells are devoid of content
• in some cases may contain certain contents
• as: -calcium oxalate as Savin
• - calcium carbonate as Cannabis
• - diosmin as Buchu
• - mucilage as Senna
31. Trichomes or hairs
• Epidermal cells are sometimes extended
outwards forming projections of variable
shapes and sizes
• If they are short and conical papillae
and the epidermis described papillosed
these appear in surface view as circles in the
middle of the cells
32. • If the trichomes are long trichomes or
hairs
- The part embeded in the epidermis foot
- The free part body
- Covered with cuticle which may be smooth as
Hyoscyamous or warty as Senna
- Either of covering type as non-glandular
trichomes or of secretory function as
glandular trichomes
- Secretions may be volatile oils or oleo-resin
34. Multi-cellular
(formed of more than one cell)
Uni-cellular
(formed of more than one cell)
Unbranched
(Simple)
Ex: Senna
Branched
Ex: Cruciferae
Unbranched
(Simple)
Branched
Non-glandular Hairs
35. Uni-seriate
(formed of one row)
Ex: Belladonna, Digitalis
Bi-seriate
(formed of two rows each
contain one cell (twin hair)
ex: Arnica flower, or more
cells ex: Calendula flower
Pluri-seriate
(formed of many
rows shaggy hair)
ex: Cumin
Non-glandular Hairs
multicellular unbranched (simple) hairs
36. Non-glandular Hairs
Multi-cellular branched hairs
Simple branched
(with uni-seriate body
ending in 2 branches)
ex: Tobacco
Stellate
ex: Boldo
Peltate
(scale hair)
Very short stalk
surrounded by plate
like structure of closely
joined cells ex: Olea
Balance hair
(T-shaped hair)
ex: Pyrethrum
37. c
Glandular hairs
I- Unicelluar (pear gland):
-not of common occurrence,
present in Piper.
- the foot is embedded in
the epidermis and the
swollen head is projecting
outside
38. II- Multicellular glandular hairs
- the most common type.
- consist of several cells and are classified into:
Uniseriate stalk Biseriate stalk and
biseriate head
(Compositae hair)
Pluriseriate stalk
and a head with
8 radiating cells
ex: Cannabis
Branched stalk
(Branched hair)
ex: Hyoscyamus
muticus
39. Uni-seriate stalk multi-cellular glandular hairs
Uni-cellular head Multi-cellular head
One-celled stalk
ex: Digitalis
2-3 celled stalk
ex: Belladonna,
Lavender
40. 1- celled stalk &
2-celled head ex:
Digitalis
1-or more celled stalk &
many celled ovoid head
ex: Hyoscyamous
Uni-seriate stalk multi-cellular glandular hairs
Uni-cellular head Multi-cellular head
very short: 1-
celled stalk & a
head of 8 radiating
cells ex: F: Labiatae
Labiacious hair
41. • These are openings in the
epidermis of stem and
leaves. They occur in both
surfaces or only on lower
surface.
• It’s a type of epidermal
structure of a great
diagnostic value
• Consists of:
- a central pore
- two similar cells; the
guard cells, kidney shaped
in Dicots while they are
dum-bell shaped in
Monocots
cStomata
42. • Stomatal number:
• The average number of stomata per square mm.
• It is of little value in distinguishing between closely
allied species
• Stomatal index:
Stomatal index = S x 100
E + S
• It is the percentage of number of stomata (S) in a
certain area to the sum of total number of epidermal
cells (E) and stomata together in same unit area.
• Stomatal index is constant for a given species
43. Types of Stomata
• 1-Moss type
- The guard cells, during
development, fuse with each
other by lysis of the separating
walls, thus the osteole becomes
surrounded by a single cell
Types of stomata according to characters of guard cells:
44. • 2- Gymnospermous:
- The guard cells are oval or elliptical and inclined to the
epidermis at an angle of approximately 45°.
• 3- Graminaceous:
- Stomata are usually rectangular in outline and the guard
cells are dumbell-shaped, thin walled ends and narrow
flat middle parts with outer and inner walls thickened.
- It is frequently with 2 subsudary cells lying parallel to
the long axis of the osteole
45. • 4- Dicotyledonous:
- Stomata are elliptical or circular in shape as seen in
surface view and surrounded by epidermal cells which
vary in characters and arrangement.
Types of stomata according to the characters and
arrangement of surrounding cells (subsidary cells):
1- Ranunculaceous (Anomocytic)
stomata:
-Equal celled type
- The stoma is surrounded by three to
five subsidary cells are of varying
number and almost of equal size
-ex: Digitalis leaves
46. • 2- Rubiaceous (Paracytic)
stomata:
- Paracytic stomata
- Parallel celled type
- The stoma is surrounded by two
or three subsidary cells , two of
which having their long axis
parallel to the axis of the osteole
- ex: Senna leaf, Coca leaf
47. • 3- Caryophyllaceous stomata:
- Diacytic stomata
- Cross-celled type
- The stoma is surrounded by two
or three subsidary cells showing
their long axis perpendicular to
the axis of the osteole
- ex: Mentha leaf
48. • 4- Cruciferous stomata:
- Anisocytic stomata
- Unequal celled type
- The stoma is surrounded by
usually three or more subsidary
cells one of which is distinctly
smaller than the others
- ex: Solanaceous leaves
50. • Palisade layer:
• formed of one or more layers of cylindrical
cells perpendicular to the epidermis with
narrow intercellular spaces which is usually
corrupted with the cortical tissues in the mid-
rib region.
• The upper palisade may form a continuous
layer as Senna or dis-continuous as
Hyoscyamus.
51. • Spongy tissue:
• formed of chlorenchyma with large irregular
cells with intercellular spaces.
• Hypodemis:
• The mesophyl is sometimes separated from
the epidrmis by one or more layers of cells
devoid of chlorenchyma called hypodermis
• This is a protective tissue or water, it may be
parechymatous, collenchymatous or
sclerenchymatous
52. • Cortical tissue:
• It is present in the mid-rib region
• Can be formed of parenchyma as in Belladonna,
or collenchyma as Uva Ursi.
• Endodermis:
• It is the inner-most layer of cortical tissue which
is usually indistinguishable in medicinal plants.
53. • Pericycle:
• present between the phloem and cortical
tissue
• mostly parenchyma but sometimes formed of
collenchyma as Digitalis
• Vascular system:
54. Bulliform cells
Bundle sheath cells with
chloroplasts
Parenchyma with
chloroplasts
Phloem
Xylem
Lower epidermis
Upper epidermis
Sclerified fibers
Collenchyma
56. I-Digitalis leaf
(Foxglove leaf)
Digitalis lanata
Allied Drug
Digitalis purpurea
Official Drug
• Origin: Dried leaves of Digitalis
purpurea and Digitalis lanata
Family: Scrophulariaceae
collected and dried rapidly at 550
C.
57. Indigenous to Europe and USA
Collection is preferably before flower expansion and should be
done in the afternoon
58. Digitalis pururea L.
[Foxglove]
Dried by:
Drying chambers at 55°C,
Vacuum drying oven,
Lyophilization
Digitalis lanata
Ebrh.
(Grecian foxglove)
Official drug Allied drug
59. Digitalis lanataDigitalis purpurea
Dried leaves of Digitalis lanata family
Scrophulariaceae
Collected and rapidlly dried in
temperature not exceeding 55-60 C
Dried leaves of Digitalis purpurea family
Scrophulariaceae
Collected and rapidlly dried in
temperature not exceeding 55-60 C
Grecian foxgloveFox glove
Oblong lanceolate to linear lanceolateShape: Ovate to oblong ovate
Entire or broadly serrateMargin: Crenate
acute to acuminateApex: obtuse
Papery, glabrousTexture: papery, wrinkled
60. Digitalis lanataDigitalis purpurea
pinnate reticulate, lateral veins leave the
midrib at very acute angle and appear
nearly parallel.
Venation: pinnate reticulate and
anastomosing near the margin .
The midrib is prominent on lower
surface, depressed on upper, giving
lamina checquered appearance.
sessilePetiole: winged
Symmetric, decurrentBase: symmetric decurrent
Showed cilia at the lower third partSurface: pubescent
Tea-like odorOdor, taste: Tea-like odor, bitter taste
1-Cardiac glycosides:
Lanatosides A, B, C, D and E (tetra
glycosides each containing an acetyl group)
N.B.They are twice to four times as active as
official drugs.
Active constituents:
1-Cardiac glycosides :
Purpurea A, Purpurea B
2-Saponins.
3-Flavonoids (luteolin).
4-Anthraquinone.
Saponin, digitonin, tigonin, gitonin
61. Digitalis purpurea Digitalis lanata
Oblong lanceolate to
linear lanceolate
acute to acuminate
pinnate reticulate
appear nearly parallel.
Entire or broadly serrate
sessile
symmetric
ovate to ovate lanceolate
obtuse
pinnate reticulate and
anastomosing near the
margin , checquered
appearance
Crenate
Winged petiole
symmetric decurrent
65. Digitalis lanataDigitalis purpurea
The epidermal cells show beaded
anticlinal walls, 10-14 celled non
glandular hairs.
Numerous irregular fragments of
epidermis with stomata of anomocytic
(ranunculaceous) type.
Glandular hairs are:
• Bicellular head and unicellular stalk
• Unicellular head and 3-10 celled
uniseriate stalk
Numerous fragments of non-glandular
hairs
Very few glandular hairs.
Calcium oxalate is absentSclerenchyma and crystals of Ca-ox are
absent
Fragments from petiole and large veins
showing spiral, annular, and reticulate
vessels
66. Digitoxose- Digitoxose-Digitoxose- Glucose
Purpurea A
Digitoxose- Digitoxose- Acetyl Digitoxose- Glucose
Lanatoside A (glycone, sugar part)
A = OH at 3,14
B = OH at 3, 14,16
C = OH at 3, 12,14
Aglycone, non sugar part
Deoxy sugar
Active Constituents
68. Digitoxin + HOAC + glucose (Acetyl derivative of purpurea A)
Lanatosides A
Partial acid or enzyme
hydrolysis
Gitoxin + HOAC + glucose (Acetyl derivative of purpurea B)
Lanatosides B
Partial acid or enzyme
hydrolysis
Digoxin + HOAC + glucose
Lanatosides C
Partial acid or
enzyme
hydrolysis
69. Lanatoside A deacetylation Purpurea A
Lanatosie B Purpurea B
N.B: deacetylation is by controlled alkaline
hydrolysis
deacetylation
N.B. Lanatosides are twice to four times as active as
official drug.
70. It is a cardio tonic.
It increases the contractility and
improves the tone of the cardiac
muscle
Slower and much stronger heart
beat produced. It is used in most
forms of cardiac failure.
It acts indirectly as diuretic
Uses:
Digitoxin is
cumulative and
its action must
be watched.
DOSE: 0.1 g of digitoxin
71. • Chemical tests of cardiac glycosides:
1- Baljet’s test
2- Kedde’s
test
for lactone ring
3- Liberman’s-
Burchard test
for steroidal
ring
4- Keller-
Killiani test
for Deoxy-
sugar
72. Boil powder with 70% alc. filter and shake with Pb
acetate, filter, add Na2HPO4, filter Filtrate (F)
1) Baljet test
(F) + (95 ml of 2% alcoholic picric acid + 5 ml of 10%
alcoholic NaOH) orange color.
Chemical test for cardiac glycosides in digitalis
leaves ( for 5 membered lactone ring):
73. 2-Keller-Killiani test:
For deoxy sugar
1- Filtrate + CHCl3 CHCl3 extract
Residue
2) Residue + glacial acetic acid (FeCl3)
+ H2SO4 on the wall of test tube
bluish green color in the upper layer
reddish brown ring (steroidal
nucleus)
evaporate
74. Name Origin Constituents Uses
2-Squill Squill is the
sliced and dried
scale leaves
from the bulb
of Urginea
maritima L.
Fam. Liliaceae
1- Cardiac
glycosides;
Scillaren A and
Scillaren B.
2- 4-11%
mucilage
3- Saponins.
•Cardiotonic
(like digitalis).
•Expectorant
in small dose
and emetic in
large dose.
75. Name Origin Constituents Uses
Red
squill
It is a variety
of Urginea
maritima
and owes its
colour to
presence of
red
anthocyanin
dissolved in
the cell sap.
1- Scillaren
A and B
glycosides
2- Toxic
glycoside
Scilliroside
Poison for
rats
77. Dried leaflets of Cassia acutifolia Delile, known as Alexandrian or
Khartoum Senna, and of C. angustifolia Vahl, known as Indian
Senna orTinnevelly Senna F. Leguminosae
Paripinnate leaflets
Compound leaves are alternate
Leaflets are opposite
Senna Leaves
79. Cultivated in Sudan (Cordovan)
exported from Alexandria
Indigenous to and cultivated
in middle and upper Nile districts
of Africa
Cultivated in south
India (Tinnevelly)
Indigenous to Somalia
and Arabia
Khartoum senna Tinnevelly Senna
Oblique lines
80. Microscopiocal differences between Alexandrian
and Indian senna
Indian sennaAlexandrian
senna
Item
Less numerous. The average
distance between each is
about six epidermal cells
More numerous. The
average distance between
each is about three
epidermal cells.
Hairs
The stomata having two or
three subsidiary cells
respectively are in the ratio
of about 7:3
Most of the stomata have two
subsidiary cells only
Stomata
19.5-22.525-29.5Vein- islet
number
14-(17.5)-2010-(12.5)-15.5Stomatal
index
85. • 1-Epidermal cells with, paracytic
stomata
• 2- Warty hairs (Non-glandular,
unicellular, curved or their
cicatrix with radiating epidermal
cells.
• 3-Hyaline angular particles of
mucilage which stain pink with
ruthenium red.
86. • 3-Cluster crystals of
calcium oxalate
4-Fragments of
lignified spiral
and annular
xylem vessels.
5-Bundles of lignified pericyclic fibres
accompanied by crystal sheath.
87. Active constituents
1- 2.5% anthraquinone :
-Glycosides ,eg: sennoside A, B, C
and D (dianthrone).
-Aglycones, free anthraquinones ,
eg, rhein, aloe-emodin
(Anthranol).
2- Flavonoid (kaempferol),
3- Mucilage and resin.
Dianthrone
88. Chemical Test
• 1- Powder +KOH----- rose red color
• 2-Borntrager’s test: Powder+ organic solvent+
dil NH4OH
• 3-Modified Borntraeger´s test:
Powder + dil.H2SO4 Filtrate + benzene +
dil NH4OH
Boil, filter then
cool
rose-red colour
(NH4OH layer)
rose-red colour (NH4OH layer)
89. Action and Uses:
Senna inhibits water absorption from the
colon, stimulates muscular coat of the
intestine to produce peristalsis. It gives soft
stools and is used as:
-Laxative (in small dose ) or purgative (in
large dose) to treat acute constipation
- Produce soft stools for patient suffering
from Hemorrhoids & Anal fissure.
-In x-rays examination or before
abdominal surgeries( for evacuation) .
Dose: 2g (infusion or decoction)
90. Contraindications
Senna is contraindicated in patients with
intestinal obstruction,
ulcerative colitis,
appendicitis.
Senna is not recommended for children younger than 2 years of age.
Pregnancy/nursing Use with caution
Senna may cause diarrhea, loss of fluids, high blood potassium, and
abdominal pain or cramping.
Long-term administration of senna may cause liver damage.
98. Atropa belladonna
الحسن ست أوراق
• Botanical Origin:
• The dried leaves with or
without the flowering tops
of Atropa belladonna,
Family: Solanaceae
99. • Shape: Simple oval to broadly ovate, narrow at the base and
slightly decurrent.
• Apex: Acute to acuminate
• Margin: Entire
• Surface: nearly glabrous
• Petiole: short
• Color: green to yellowish green.
• Taste: Bitter and acrider
• Stomata: Anisocytic
• Ca-ox: Idioblasts or microsphenoidal crystals
100. • Hairs:
• a-Glandular hairs:
• 1- Clavate hair with 1-3 celled stalk and
rounded or club shaped multicellular head.
• 2- 4-6 celled stalk and 1 celled ovoid head.
• b- Non-glandular hairs:
• Uniseriate, 2-6 celled with thin walls and
smooth cuticle.
101. • Powdered Belladonna:
• Powdered belladonna leaf is green to
brownish-green, characterized by:
1- Fragments showing epidermis consisting of
sinuous walled cells and striated cuticle
and stomata of anisocytic type.
2- Numerous green fragments of mesophyll
with idioblasts of microcrystals of calcium
oxalate.
3- Occasional non-glandular hairs, uniseriate,
2-6 cells.
4- Fragments of glandular hairs. One with
uniseriate stalk and unicellular head and
the second has a short unicellular stalk and
globular multicellular head (4-6 cells).
102. • Active Constituents:
• 1- Alkaloids: - Hyoscyamine,
- Scopolamine (hyoscine),
- Belladonine,
- little amount of Atropine.
• 2- Volatile bases: - Choline,
- Pyrridone,
- N-methyl-pyroline,
- trimethylamine.
• 3- Fluorescent substance: having coumarin
structure (Scopoletin).
112. • Actions and Uses:
• Atropine, Hyoscyamine and Scopolamine
(Hyoscine) cholinergic blocking
agents.
• They decrease gastric and saliva secretion,
increase heart rate (by depression of the
vagus nerve).
• They depress the motility of the
gastrointestinal tract and act as antispasmodic
(sedative effect) on various smooth muscles
(uterus, bladder and biliary tract).
113. • They stimulate the respiratory center.
• Externally Atropine dilates the pupil of the eye
(Mydriatic effect).
• The action of Scopolamine (Hyoscine) differs
from that of Atropine and Hyoscyamine in that
there is no central nervous system stimulation
but rather a narcotic or sedative effect
predominates.