Principals of Flowering Plants Taxonomy

Principals of Flowering Plants Taxonomy BOT 222

Dr. Najat Abdulwahab Bukhari

Lecture 3

University Vision and Mission

Vision:

To be a world-class university and a leader in developing Saudi Arabia’s knowledge economy

Mission:

To provide students with a quality education, conduct valuable research, serve the national and international societies and contribute to Saudi Arabia’s knowledge economy through learning, creativity, the use of current and developing technologies and effective international partnership.

College of science vision and Mission

Vision

:

To be a leader in basic science, its applications and culture to contribute to building the knowledge society.

Mission:

To offer study programs and developed research projects capable of providing society with knowledge and trained personnel through a stimulating environment for learning, creativity and scientific research with continuing quality to ensure optimal use of technology and general partnership.

Vision: upgrading the academic and research to keep pace with scientific progress and requirements of society. Mission:Development of Academic process and develop scientific research through strategic planning and a clear vision for science and technology at the country level. As well as training of national cadres, and the introduction of a methodology developed to meet the different needs of society, and to serve the various research and developmental projects in the community

Botany department Vision and Mission

Plant taxonomy use many characters :

Morphology

Anatomy

Photochemistry

Cytology

Palynology

Plant Morphology is the general term for the study of the

morphology

(physical form and external structure) of

plants

:

Vegetative characteristics: (leaves and stems).

Floral characteristics: ( Flower and inflorescence )

Flower is valuable in plant classification and taxonomy, It is considered one of the most important part of the plant in the plant classification process for the following reasons:The flower is less affected by different environmental and climate conditions. Contain many basic and obvious differences that distinguish the various plants . Therefore, plants are arranged into several Orders, families , Genus and species . For example: aquatic plants may be similar in outward appearance and internal structure, but differ in the composition of flowers and plants as well as xerosis and salt-loving plants.

The flower is a unique thing in the life of plants angiosperms ,as it is the axis that holds reproduction in organs in the flowering plants, and it’s the key part of sexual reproduction

flower is regarded as a modified

stem

with shortened internodes and bearing, at its

nodes

, structures that may be highly modified

leaves

.

Flowers may be attached to the plant in a few ways. If the flower has no stem but forms in the

axil

of a leaf, it is called

sessile

. When one flower is produced, the stem holding the flower is called a

peduncle

.

If the peduncle ends with groups of flowers, each stem that holds a flower is called a

pedicel

. The flowering stem forms a terminal end which is called the torus or receptacle. The parts of a flower are arranged in

whorls

on the torus. The four main parts or whorls (starting from the base of the flower or lowest node and working upwards) are as follows:

Calyx

: the outer whorl of

sepals

; typically these are green, but are petal-like in some species.

Corolla

: the whorl of

petals

, which are usually thin, soft and colored to attract animals that help the process of

pollination

. The coloration may extend into the

ultraviolet

, which is visible to the

compound eyes

of insects, but not to the eyes of birds.

Androecium

: one or two whorls of

stamens

, each a

filament

topped by an

anther

where

pollen

is produced. Pollen contains the male

gametes

.

Gynoecium

: one or more

pistils

. The female reproductive organ is the

carpel

: this contains an ovary with ovules (which contain female gametes). The sticky tip of the pistil, the stigma, is the receptor of pollen. The supportive stalk, the style becomes the pathway for

pollen tubes

to grow from pollen grains adhering to the stigma, to the ovules, carrying the reproductive material.

a bract is a modified leaf or leaf like part just below and protecting an inflorescenceBracts are often (but not always) different from foliage leaves, for example being smaller, larger, or of a different color or texture.Bracts are found in the front of the flower ( the part of flower facing the bracts is called “Anterior Side”) and the other side “Posterior Side”.

bracteole

or

bractlet

: a small bract that arises on a pedicel instead of subtending it.

Bractlets

can be 2 in

dicotyledons

, and one in

monocots

one which may be green or

squamous

They can differ from each other on where are inserted.

Receptacle

is the thickened part of a stem from which the

flower

organs grow.

It is often a shape of bulging disc or a rectangular or circular or in the platoon as the

cruciferae

family.

When the receptacle elongate between the Corolla and calyx and its called

Anthophore

,

and between the corolla and the stamen it is called

Andero

gynophore

. Or elongate between

Anderoecium

and

gynoecium

it is called

Gynophore

.

Receptacle

contain glands to attract insects so the process of pollination and fertilization, nectar is a sugar syrup .

The receptacle (grey) in relation to the

ovary

(red) in three types of flowers:

hypogynous

(I),

perigynous

(II), and

epigynous

(III)

Why is the flower the most important parts of the plant in the classification process:

The least part of the plant affected by different environmental and climate conditions.

Contain many basic and obvious differences that distinguish the various plants

(For example, aquatic plants may be similar in outward appearance and internal structure, but differ in the composition of its flowers to belong to different plant families).

The flower is a unique thing in the life of floral plants angiosperms and It is also the axis that holds the reproduction organs in the flowering plants.

The center of plant reproduction as it is composed to ensure that sexual reproduction and fertilizing eggs .

Calyx

Calyx:

Is composed of a number of sepals may be rarely 2-3 or 4 in one specie the

cruciferae

family or 5 in most of the families. The calyx is the outermost whorl of a flower.

Function:

protection of the flower internal organs.

Sepals

are often green but sometimes it takes the petals colure (

Petaloid

sepalous

).

The number of sepals often equal to the number of petals.

Sepals are often green but sometimes it takes the petals colure ( Petaloid sepalous). The number of sepals often equal to the number of petals.

Sepals often form one ring, but it may sometimes be in two rings. sepals may be loose, as in roses and or it could be fused, as in peas.

There may be additional external

pericalyceal

called “Epipetalous" as in the cotton flower or

Malvavceae

family.

Calyx could stay on the receptacle and does not fall after the pollination and fertilization, in this case it is called “presistant”, as in the eggplant.

Calyx

could fall early when the flower opens, in this case it is called “

Cadocous

” as in the Poppy.

In some cases specially in the tropical flowers the calyx is in the form of portfolio wrapped around a floral bud, and filled with water.

Sepals help in the process of spreading seed and fruit.

When the

petals

and sepals of a flower look similar they are called

tepals

.

They both form

Perianth

.

Calyx shapes:

Tubular

Petaloid

Pitcher-like

Labaitae

Bell-form