pinophyta conifers)

8/3/2019 Pinophyta Conifers)

1/15

Jessamine Chong

Pinophyta

Lower 6 4 (2011)Pn. Suriani


2/15

Coniferophyta

Pinophyta are the scientific division for conifers.Also known as Coniferophyta.

The division has 8 families, 68 genera and 630

speciesThey are cone-bearing seed plants with vasculartissue; all extant conifers are woody plants,the great

majority being trees with just a few being shrubs.Examples are : cedars, firs, junipers, pines andredwoods


3/15

They exists in the the boreal forests of the northernhemisphere but also in similar cool climates in mountainfurther south.

Boreal conifers have many winter time adaptations

The narrow conical shape of northern conifers and theirdownward-drooping limbs help them shed snow.

Many of them seasonally alter their biochemistry to makethem more resistant to freezing, called hardening

They are also of great economic value primarily for timberand paper production; the wood of conifers is known assoftwood

Dominant in colder and arctic regions


4/15

Taxonomy and naming

Kingdom : Plantae

Phylum : Coniferophyta

Class : PinopsidaOrder : Pinales or Coniferae (also known as Coniferales)

Family : Pinaceae (the pine family)

Genus : PinusSpecies : monticola (Western White Pine)


5/15

Morphological Characteristics

All conifers are woody plants ,majority havingmonopodial growth (a single, straight trunk with sidebranches) with strong apical dominance

Many have distinctly scented resin, secreted to protectthe tree against insect infestation and fungal infectionson wounds

Fossilized resins hardens into amber

The worlds tallest is the Coast Redwood( Sequoiasempervirens ) with a height of 115.5 meters

The largest is the Giant Sequoia( Sequoiadendrongiganteum ) with a volume of 1486.9 cubic meters


6/15

The thickest which is the Montezuma Cypress( Taxodiummucronatum ) with a 11.42 meters in diameter

The oldest is the Great Basin Bristlecone Pine ( Pinuslongaeva ) is 4700 years old

The worlds tallest, largest,thickest and oldest livingthings are all conifers


7/15

Description

Needle-shaped leaves or scalelike leaves

Straight trunks with horizontal branches

Staminate (pollen producing ) conesMost also bear ovulate or seed-bearing cones


8/15Coniferous Leaves


9/15

Life Cycle

To fertilize the ovum, themale cone releases pollenthat is carried on the wind tothe female cone. (Male andfemale cones can be foundon the same plant)

The pollen fertilizes thefemale gamete (located in thefemale cone).*

A fertilized female gamete(called a zygote) developsinto an embryo


10/15

Along with integument cells surrounding the embryo, a seeddevelops containing the embryo. This is an evolutionarycharacteristic of the gymnosperms.

Mature seed drops out of cone onto the ground.

Seed germinates and seedling grows into a mature plant.

When the plant is mature, the adult plant produces cones andthe cycle continues.


11/15

Reproduction

Reproduction structures are the cones

Large female and smaller male cones are found on the sameplant

The ovules are not enclosed by the ovary wall

After fertilisation, the seeds formed are not enclosed by thefruit wall (pericarp)

Thus, they are in the Gynosperm group.

Slow to reproduce


12/15

Reproduction


13/15

CONFIERS AND THEIR CONES

While there are male and female

mosses, conifers produce two typesof cones on the same tree. One ofthe cone types gives off pollen (thestaminate cone). The other type ofcone catches the pollen if the wind ismoving in the right direction. Betteryet, the wind blows the pollen toanother conifer of the same species,and a cone (called the ovulate cone)

catches the pollen. Again, the pollenand megaspore (receiving haploidcell) are haploid and combine to forma diploid cell. That diploid cell grows

into a zygote (baby conifer) thateventually lives in a seed.


14/15

Conifer Cones

Korean Pine Cones


15/15

pinophyta conifers)

Documents