PRINCIPALS OF FLOWERING PLANTS TAXONOMY

BOT 222

Dr. Najat Abdulwahab Bukhari

Lecture 12

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.

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

Course Description Topics to be Covered

Topic No ofWeeks

Contact hours

- Historical review of plant taxonomy (industrial , natural, evolution)

1 2

- Nomenclature 1 2- Classic taxonomy (morphological taxonomy of vegetation and floral characters – Fruits and seed characters.

5 2

- Key to taxonomical unites. 1 2- Fertilization and seed formation 2 2- The different kinds of fruits 2 2- The sexual differentiations of flowers and their fertilization

2 2

14 14

Floral formula Floral formula is a summary of the structure and

components of a flower using symbols and numbers. The parts of the flower are represented by: K (for calyx) C (for corolla) P (for perianth) A (for androecium) G (for gynoecium) The symbol G has a line above it to indicate an inferior

ovary and a line beneath it to indicate a superior ovary

The sexuality of the flower is represented by the standard symbols for males (♂) and females (♀).

Bisexual

The symbols representing symmetry include: ygomrphic Actinomorphic  Zygomorphic 

"M" for a monoecious system and "D" when dioecious. (PM) polygamomonoecious (PD)polygamodioecious

∞ indicates an indefinite number of parts (more than 12).

( ) If the parts are fused. ….+…. if they are in separate groups * = staminode; a sterile stamen Ḡ = ovary inferior to insertion point of the

other whorls. G = ovary superior to insertion point of other

floral whorls Ḡ = ovary inferior to superior - variation exists

The structure of a flower is composed by the previous floral formula and appropriate symbols and the placentation type within the ovary. Any descriptive terms can be added to describe an important floral character such as the sub- calex or sterile stamens, etc. .....

How to dissect a flower

Using the above rules we can follow these steps and the observations:Floral Diagram:Floral diagram is the stylized cross sections of flowers that represent the floral whorls as viewed from above, showing the arrangement and number of parts in a flower, ovary is drawn as a cercal in the centre.Posterior sidePeduncle.

In the case of florets the focus is to the large flower (axis of the rest of the flowers).

If exists the bract is drawn at the bottom of the paint, to the Anterior side of the flower.The floral whorls represented by circles.

Longitudinal Section

1- parts of flower drawn by order of parts on the pedicles.

2- taking in consecration the ratio of the lengths of these parts maintaining the proportions of the real lengths .

Positions of sepals and petals do not represent the sector in the longitudinal and represent only the full parts and the fusion places of docking between the parts to each other while maintaining the ratio

The longitudinal sector shows the stamens position. Whether its out of pedicel or . And shows the various shapes of calyx.

Floral Diagram Symbols II

Sample floral diagrams

Sample Floral Diagrams Described

Distribution of sex in flowers

Poly sexual “ Mult sexual”

Poly gamy

Multi sexual flowers , male and

female flowers

Bi sexual

Dio gamy

Some flowers formed having stamens and

pistils :

Mono sexual

Mono gamay

Mixed pollination

Allo gamy

Mono sexual

Mono gamy

2 -Dioecious

Having the male and female organs in separate and

distinct individuals; having separate sexes

Phoenix dactylifera

1 -Monoecious

Having separate male flowers and female flowers on the

same plant, as in corn

Zea mays

Bi sexual

2 -Dichogam the condition of having

stamens and pistils mature at different times “Allo gamy “

followed with Auto gamy

1- Homogamy

the condition of having stamens and pistils mature

at the same time

Two situations:

Homogamy

Cleisto gamy

Failure of a flower to open, stamens and styles mature “self pollination.

Chasmo gamy

A flower which is chasmogamous opens

and exposes the stamens and styles.

Dichogam

Protogamy

Stamens mature before styles. As

in strawberry.

Protandry

Styles mature before stamens.

Compound family