PHYLUM

CONIFEROPHYTA

Plant Kingdom

Brooke Loegering

1Monday, May 21, 12

Introduction to Coniferophyta

FirYew Pine

FernCedar Birch

Larch Cypress Spruce

RedwoodHemlock Juniper

Characteristics

- Mostly tall trees w/ persistent central trunk.

- Many are long-lived.

- Mostly evergreen.

- Needle-like or scale-like leaves.

- Produce cones.

- No outer-covering or shell around their seeds.

- Reproduce via wind pollination.

- Do not bear fruits.

- Produce different male & female spores

(heterosporous).

2Monday, May 21, 12

Introduction to Coniferophyta

What distinguishes them from other member of the same kingdom?

Pollination- Angiosperms rely on plants & animals: This helped with the evolution of flowers to entice the insects and animals to spread their pollen.- Gymnosperms rely on wind as their main source of pollination, which leads to trees with very similar genotypes in a very concentrated area.

Time from pollination to fertilization- Angiosperms: Pollinate & fertilize almost simultaneously.- Gymnosperms: Pollen often sits within the cone for up to 15 months or more before fertilization occurs.

Double fertilization- Angiosperms: One sperm fertilizes the egg while the other combines to form an endosperm.- Gymnosperms: No double fertilization.

Fruit- Angiosperms: Produce fruit, evolve with mammals to entice animals to spread pollen.- Gymnosperms: Seeds without fruit.

3Monday, May 21, 12

Introduction to Coniferophyta

Characteristics to distinguish the genera & species from one another- Size/shape of cone produced

- Size/shape of leaves

- Length of lifespan

- Arrangement of leaves

- Pollen grains

4Monday, May 21, 12

68 genera and 630

species

in the phylum.

Two extinct

members of this

phylum:

- Cheirolepidiaceae

- Walchiaceae

5Monday, May 21, 12

Anatomy, Micro-Anatomy and Physiology

6Monday, May 21, 12

Environment & Habitat

There are not any particular, special conditions it needs to grow and survive. Although, typical conditions include dry areas, long cold seasons or nutrient deficient soils such as acidic swampy mucks or sandy areas of the West.

The organism lives in both hemispheres. It dominates forests of Western US and Canada as well as tropical regions.

It is NOT survival dependent on the presence of other organisms.

7Monday, May 21, 12

Life Cycle (Reproduction)The life cycle is a slow, two-year process.

1. To fertilize the ovum, the male cone releases pollen that is carried on the wind to the female cone. (Male and female cones can be found on the same plant)

2. The pollen fertilizes the female gamete (located in the female cone).

3. A fertilized female gamete (called a zygote) develops into an embryo.

4. Along with integument cells surrounding the embryo, a seed develops containing the embryo. This is an evolutionary characteristic of the gymnosperms.

5. Mature seed drops out of cone onto the ground.

6. Seed germinates and seedling grows into a mature plant.

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

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Life Cycle (Reproduction)

Oldest living conifer is over 4,700 years old.

Reproduction occurs every 12-14 months.

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Genetics, Phylogenetics, Evolution

Have genetic studies on this organism revealed new insights as to how this organism is related to members of other phyla?

Yes, the diversification of Conifers during the Mesozoic helps to mark a significant change in the world's flora. Paleozoic flora was dominated by ferns and clubmosses (Paleophytic flora). The Paleophytic flora gave way to a Mesophytic flora during the Triassic period. Woody seed-bearing plants and their relatives dominated Mesophytic flora. Thus, the change from Paleophytic to Mesophytic represented a change in reproductive strategy; from spore producers to seed producers. Conifers, cycads, and ginkgoes diversified during this time and dominated the landscape (Kenrick & Davis, 2004, p. 143).

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