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Pharmacognosy- 1
PHG 222
Prof. Dr. Amani S. Awaad
Professor of Pharmacognosy
Pharmacognosy Department,
College of Pharmacy
Salman Bin Abdulaziz University,
Al-Kharj. KSA.
Email: [email protected]
What is The meaning of Botany.
To know Morphology.
TO memorize plant organ systems
To know what is anatomy.
To study anatomy of plant organs.
Medicinal
Botany
Botany
What is Botany?
Botany, also called plant science(s) or plant biology, is the science of plant life and a branch
of biology.
The term "botany" comes from the Ancient Greek word (botanē) meaning "grass", or "fodder“.
Botany originated in prehistory as herbalism with the efforts of early humans to identify edible,
medicinal and poisonous plants.
Many studies one of them is the study of plants morphology.
What is the benefits of botanical studies?
1-increase and improve our supply of medicines, foods, fibers, building materials, and
other plant products.
2-Conservationists use botanical knowledge to help manage parks, forests, range lands,
and wilderness areas.
3-Public health and environmental protection professionals depend on their
understanding of plant science to help solve pollution problems
Botany
Morphology & Anatomy
Plant Morphology or phytomorphology is the study of the physical
form and external structure of the plant.
This is usually considered distinct from
Plant Anatomy, which is the study of the internal structure of
plants.
Plant morphology and anatomy are very important for description and
identification of plants.
Classification of flowering plats is based mainly on the morphology of
the flowers
Plant Organization
A plant has two organ systems:
1- The shoot system:
is above ground and includes the organs such as
leaves, buds, stems, flowers, and fruits.
2- The root system:
includes those parts of the plant below ground,
such as the roots, tubers, and rhizomes.
Plant Organs
Organs: tissues that act together to
serve a specific function
• Leaves
• Stems
• Roots
Leaves
(Photosynthetic factories of the plant)
BLADE
• Function: Photosynthesis – food production fro the whole plant.
• Consists of:
- Blade (= lamina): Flat expanded area.
- Petiole (= stalk): Stalk that connects leaf blade to stem, and transports materials
- Stipule: Is an outgrowth of the lower zone of a young leaf, part of the leaf base
STIPULE
Leaf types
Simple leaves:
Consists of single
leaf blade (lamina).
Compound leaves:
Consists of separate leaflets
each has separate lamina and
secondary leaf stalk but never
have stipules and auxilary buds.
leaf shapes, Margins, Apices, and Bases
Shapes
Apices
Bases
Margins
Stems
- Support leaves and fruits
- Conduct water and sugars throughout plant (xylem and
phloem)
- Normally divided into nodes and internodes
Types of stem
The Stem
A) Over ground .
Normal types in majority of plants
B) Underground stem
Underground stems are modified plant structures that derive
from stem tissue but exist under the soil surface
1. Bulb, in which the shoot consists of very short vertical stem
(bearing roots below) and fleshy storage leaves (e.g. Onions).
2. Corm, in which the shoot consists mostly of vertical storage
stem(e.g Colcicum)
3. Rhizome, in which the stem is horizontal and underground (e.g.
Zingiber officinale, Ginger).
4. Tuber, which consists of a thick, underground storage stem,
usually not upright, (e.g., Solanum tuberosum, Potato)
The flowers
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants
• The typical flower consists of four sets of flower parts arranged on a
short swollen structure called receptacle. The four parts from outside
are:
• sepals (collectively called calyx) are the outermost organs below the
petals which most resemble leav
• petals (collectively called corolla) are the showy part of most
flowers. In some flowers, the petals are green and are called
sepaloid.
• Stamens (collectively called androecium) are the male sexual
organ of the flower. A stamen consists of an anther which contains
the pollen, supported by a thin filament.
• Pistils, which are often called carpels, (collectively called
gynoecium) are the female sexual organ of the flower which are
usually vase-like in appearance..
The flowers
• Pistils, which are often called carpels, (collectively
called gynoecium) are the female sexual organ of the
flower which are usually vase-like in appearance..
Stamens (collectively called androecium) are the male
sexual organ of the flower. A stamen consists of an
anther which contains the pollen, supported by a thin
filament
The root
root, in botany, that part of a plant
normally underground. Its primary
functions are anchorage of the plant,
absorption of water and dissolved
minerals and conduction of these to the
stem, and storage of reserve foods.
The root
1-Aerial roots
These are adventitious roots that don’t enter the soil . It Absorb water
and minerals from the air Mostly epiphytic plants have this type of roots
2-Prop roots
Grow from the base of the stem Serve as to support of the plant with weak
stems
3-Tap Root System
Tap root or the primary root is the most common type of root system and it
consists of the tap root also known as the primary root
4-A fibrous root
(sometimes also called adventitious root system) is the opposite of a taproot
system. It is usually formed by thin, moderately branching roots growing
from the stem y part of the plant other than the radicle are known as the
adventitious roots
Anatomy
(plant histology)
Also known planthistology, is concerned
with the microscopic
structure of the tissues,
cells and organs of plants.
Anatomy
(The leaves)
•The outer epidermis is covered with a waxy
cuticle to prevent water loss ◦This also
prevents gas exchange :
•Stomata (sing = stoma) are pores in the
surface of leaves which allow for gas
exchange ◦Pore surrounded by two guard cells
◦Guard cells open and close to allow gas
exchange
•The underside of leaves is usually covered
with hairs (trichomes). Functions: catch
water, reduce airflow, produce wax
Botany
Anatomy
(The stems)
Stem usually consist of three tissues, dermal tissue,
ground tissue and vascular tissue.
Morphology
Anatomy
(The root)
Epidermis – The outer layer of cells
Root hairs – Absorptive unicellular extensions of epidermal cells of a root..
Cortex – Primary tissues of a root bound on the outside by the epidermis
and on the inside by the endodermis. In a carrot, the cortex becomes a
storage organ.
Endodermis – A single layer of cells in a root that separates the cortex
tissues from the pericycle.
Pericycle – A layer of cells immediately inside the endodermis. Branch
roots arise from the pericycle.
Vascular system – Bundle of xylem and phloem tissues
Phloem tissue conducts products of photosynthesis from leaves
throughout plant including down to the roots.
Xylem tissue conducts water and minerals up from the roots up
through the plant
Pith-is composed of soft, spongy parenchyma cells, which store and
transport nutrients throughout the plant. The pith is encircled by a ring of
xylem; the xylem, in turn, is encircled by a ring of phloem.
Shape of Plant tissues
A tissue is a group of coherent
cells having similar form and
function and have common
origin.
Tissues are classified according to
stage of development to:
Meristematic tissue: the cells
have the ability of division.
Mature (permanent): the cells lost
the power of division.
1- Parenchyma
Characters:
1- Simple living cells.
2- Have primary cellulosic
thin wall with simple pits.
3- Have intercellular spaces.
4- They may be elongated,
isodiametric or lobed.
2- Collenchyma
Characters:
1- Simple living tissue.
2- Have primary cellulosic thick wall
with simple pits.
3- May have intercellular spaces.
4- They are elongated cells
Types:
Lamellar: thickening on tangential
walls.
Angular: thickening on angles between
the cells.
Lacunar: thickening on walls facing the
intercellular spaces.
3- Sclerenchyma
They are dead cells when
mature with thick
secondary walls, they
are elastic tissue used
for mechanical
support.
Sclerenchyma has two
types;
fibers
fibres and sclereids.
Sclereids
4- Xylem
It is the water
conducting tissue
which consists of
vessels,
tracheids,
fibres and
parenchyma.
5- Phloem
Phloem is the food
conducting tissue
which is formed of
four elements;
sieve elements,
companion cells,
parenchyma and
fibres.
6- Epidermis
epidermal cells
It occurs on the
surface of plants
and it is a complex
tissue consisting of
stomata
Trichomes &(hairs)