Presentation on theme: "Vascular Plants With Seeds Divided into two Groups."— Presentation transcript:
Vascular Plants With Seeds Divided into two Groups
The Two Groups Gymnosperms (with 3 phyla) Angiosperms (with 1 phylum)
Phylum Coniferophyta Often called gymnosperms Gymnosperms: the seed plants that do not first produce a flower before the seed Means “naked seed” – produce seeds not covered by the walls of an ovary Do not form flowers or fruits Produce cones or cone-like structures Conifer refers to the cones All conifers produce seeds in cones
Two Types of Cones Staminate and Ovulate
Staminate Cones The pollen-producing cones Small, green, and inconspicuous near the tips of the branches Shed after the pollen season is over
Ovulate Cones The seed-producing cones Larger than staminate cones Size range: 1-2 inches Woody structures consisting of layers of cone scales Seeds develop between the cone scales Seeds are generally winged
Pine Tree Life Cycle Tree produces cones Pollen is carried by the wind from staminate cones to ovulate cones Pollen lands on the open scales of the ovulate cone The scales then close tightly (in many pines the cone begins to point downward Ovum is fertilized When the seeds are mature and environmental conditions are right, scales open and release seeds
Noteworthy Conifers: Douglas-fir The Douglas-fir, named for David Douglas, a 19th century Scottish botanist. Great strength, stiffness and moderate weight make it an invaluable timber product said to be stronger than concrete. Averaging up to 200' in height and six feet in diameter, heights of 325' and diameters of 15' can also be found. Provide more than ¼ of the timber cut in the U.S.
Noteworthy Conifers: Sequoia In central California Some are among the oldest living things on earth (2,000 – 3,500 years) 273 feet tall 84 feet circumference Bark 1 foot thick
Noteworthy Conifers: Bristlecone Pines The oldest living bristlecones are found in the White Mountains of California. The oldest known living tree, discovered in 1957, is a 4,723-year-old patriarch named Methuselah. The oldest bristlecones are more than 4,000 years old. Egypt’s pyramids were under construction when these trees were seedlings!
Noteworthy Conifers: Coast Redwood Redwood trees are the tallest living things on earth. Some grow more than 350 feet tall.