2. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
THE WORD GYMNOSPERMS ORIGINATES
FROM GREEK “GYMNOS” MEANING
NAKED AND GREEK “SPERMA” MEANING
‘SEEDS’
5. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
The gymnosperms
- the first seed plants
-Bear ovules and seeds exposed
on the plant surface. ( in contrast
to angiosperms),
Hece name= gymnosperm
-Include the oldest and largest
trees known
Bristle cone pines -
the oldest trees
4767 years.
Giant Redwood(the tallest
tree
6. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
.
GYMNOSPERMS
are perennial and evergreen. Woody
( shrub and trees), not herb.
are xerophytic and terrestrial but never aquatic.
Plants possess tap roots. In some cases, roots show
symbiosis with certain algal cells as in coralloid
Coralloid roots are found in Cycas and mycorrhizal
roots are found in Pinus.
Leaves may be monophorphic (same type of leaf) or
dimorphic (Scale leaves and Photosynthetic leaves)
8. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
Stems are characterized by the presence of
collateral endarch vascular Bundle
Vessels are absent (exception: Gnetum: the
most advanced group in Gymnosperm
T S Stem (Cycas)
9. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
Flowers (cones) are composed of only microsporophyll and megasporophyll
( No sepal and no petal.)
.Gymnosperms are heterosporus ,
plants Dioecious/Monoecious
Cones Unisexual
Double fertilization doesn’t take place in Gymnosperm.
Embryo is developed at the end of a long suspensor.
Cleavage polyembryony occurs.
Archegonia are produced in the ovules of all Gymnosperms except Gnetum.
10. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
Characteristics of Gymnosperms
Carpel is not differentiated into ovary,
style and stigma.
Ovules are borne naked on the surface
of megasporophylls.
.Then pollen grains directly fall or
settle on micropyles.
The endosperm is formed before
fertilization.( HAPLOID.)
Gymnosperms do not reproduce
vegetatively by cutting, budding etc.
Zygote exhibits free nuclear division.
Produce seeds, not fruits
Carpel of Angiosperm
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In 1965, Sporne classified Gymnosperms into 3 classes:
1: 1 Pteridospermales or Cycadofilicales (Lyginopteris,
O : 2 Bennettitales or Cycadeoidales (Cycadeoidea,
r 3 Pentoxylales (Pentoxylon)
4 Cycadales (Cycas, Abies)
1: Cordaitales (Cordaites)
2: Taxales (Taxus)
O 3: Coniferales (Pinus)
4: Ginkgoales (Ginkgo biloba, living fossil)
1: Gnetales (Gnetum, Ephedra, Welwitschia )
Class 1:
Cycadopsida d
Order
s
Class 2:
Coniferopsida
Class 3:
Gnetopsida
Order
CLASSIFICATION
13. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
Food Medicine
Timber
OIL
Industrial
Asthetic
value
ECONOMIC
IMPORTANCE
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•
Cycads are good source of starch, Source
Plant
Cycas rumphi ,
•Seeds of Pinus gerardiana and Gnetum
seeds are edible known as chillgoza
•Kaffir bread is a type of bread prepared from
the stem pith of Encephalatos
•Young leaves of cycas are cooked as
vegetables in some parts of the world
FOOD
15. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
•
Paclitaxel (PTX) sold as Taxol, used for
chemotherapy against cancer.
Source plant -Taxus
• Ephedrine is an alkaloid extracted
from the Ephedra. It is used in the
treatment of asthma, cough, cold,
bronchitis.
• Juice from the young leave of the
phylum Cycas revoluta is used for curing
blood vomiting.
• Cycas guns: is an antidote against
snake bite and it is also used to cure
malignant ulcer
MEDICINE
16. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
•
Gymnosperms are a good source of timbers;
they are mainly softwood which is beneficial
in furniture settings and construction
purposes
•The woods from conifers are resistant to
insects and fungus
•Woods from Gymnosperms are also durable
and of light weight
•A specie of gymnosperm called Agathis
australis is the largest timber producing tree
in the world
•Plywoods and other scented woods are all
products processed from Gymnosperms.
17. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
• Edible oil is extracted from the
seeds of Cycas revoluta, Macrozamia
and many others
• Red cedar wood oil is extracted
from the heartwood of juniperus
virginiana is used in oil immersion
microscopy.
• Oil from Gymnosperms are also
used in deodorants and soaps
OIL
18. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
•
Tannins extracted from
the bark of Pinus and
Sequoia are used in the
leather industry
•Newspapers, writing
papers, and printing
papers are prepared from
the wood pulp of Pinus,
Picea and Abies
Industrial
product
19. 13-02-2021 Lntroduction to GYMNOSPERM Sadhna pandey
• Ornamental plants are plants that are grown for decorative purposes
• Cycas Ginkgo and other pines, and Gnetum species used in decoration of lawn, parks etc..
• Various species of gymnosperms can also be grown as Bonsai
Ornamental plants
Ornamental plants