Prof. Dr. Amani S. Awaad

Professor of PharmacognosyPharmacognosy Department,

College of Pharmacy

Salman Bin Abdulaziz University,

Al-Kharj. KSA.

Email: amaniawaad@hotmail.com

Pharmacognosy- 1

PHG 222

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

BotanyWhat 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 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 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 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 OrgansOrgans: tissues that act together to

serve a specific function

• Leaves

• Stems

• Roots

Leaves(Photosynthetic factories of the plant)

Leaf types

Simple leaves:

Consists of separate leaflets

each has separate lamina and

secondary leaf stalk but never

have stipules and auxilary buds.

Consists of single

leaf blade (lamina).

Compound leaves:

• 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

BLADE

STIPULE

leaf shapes, Margins, Apices, and Bases

Apices

Bases Margins

Shapes

Stems

- Support leaves and fruits

- Conduct water and sugars throughout plant (xylem and

phloem)

- Normally divided into nodes and internodes

The Stem

Underground stems are modified plant structures that derive

from stem tissue but exist under the soil surface

Types of stem

B) Underground stem

A) Over ground .

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 storagestem(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)

Normal types in majority of plants

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 ashort swollen structure called receptacle. The four parts from outsideare:

• 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

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

2-Prop roots

Grow from the base of the stem Serve as to support of the plant with weak

stems

Also known plant-histology, is concerned with the microscopic structure of the tissues, cells and organs of plants.

Anatomy

(plant histology)

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

MorphologyAnatomy

(The stems)

Stem usually consist of three tissues, dermal tissue,

ground tissue and vascular tissue.

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.

Anatomy

(The root)

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.

Characters:

1- Simple living tissue.

2- Have primary cellulosic thick wallwith 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.

2- Collenchyma

3- Sclerenchyma

They are dead cells when

mature with thick

secondary walls, they

are elastic tissue used

for mechanical

support.

Sclerenchyma has two

types;

fibres and sclereids.

fibers

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

It occurs on the

surface of plants

and it is a complex

tissue consisting of

epidermal cells

stomataTrichomes &(hairs)