Download Gymnosperms

Gymnosperms: naked seed plants
I.
Characteristics of Gymnosperms
A. Gymnosperms include: pines, firs, spruces, ginkgos,
and cycads.
B. Possession of a true seed.
C. Contain secondary growth that forms woody stems
D. No water necessary for sperm to reach egg.
E. Leaves usually needle-like; exceptions exist.
F. Sweden’s pines produce 75,000 tons of pollen each
Spring.
II. Division Pinophyta
A. Pines reproduce using male and female cones on the
same tree.
B. The first artificial Christmas trees were sold by Sears
and Roebuck
C. The oldest living plants in the world are Bristlecone
pines. One is 4,737 years old.
D. Female pine cones and male cones contain 1n or
haploid sex cells before fertilization.
E. After fertilization, the female cones develop 2n
diploid seeds.
F. The state flower of Maine is the cone of the White
Pine.
G. Female pine cones contain a pollination droplet in
their ovules to capture pollen grains.
Eastern Redcedar
Typical Pines
White Pine
Blue Spruce
Juniper with “berries”
Bristlecone Pines
are the oldest
living plants in
the world.
III. Division Ginkgophyta
A. Ginkgos are also known as the Maidenhair Trees
B. They are extinct in the wild.
C. Ginkgo seeds are very fleshy, smell terrible, and are
only found on female trees.
D. Ginkgos lose all of their leaves every fall, the only
completely deciduous division in all of the
Gymnosperms.
E. Ginkgos are dioecious, meaning they have separate
male and………………………… female trees.
In the fall,
ginkgo trees
are greatly
loved for their
yellow foliage,
though
females are
not usually
planted.
You can distinguish a Ginkgo from
other gymnosperms by its fan shaped
and bi-lobed leaves. All Ginkgo trees
have a relatively primitive vascular
system. The veins continuously divide
into twos. This vein pattern
(dichotomous venation) is unique to
the Ginkgo.
IV. Division Cycadophyta:
A. Cycads are all dioecious, as are the ginkgos.
B. The ONLY wild Cycads in the USA are in Florida,
though they can be grown ornamentally in other
areas.
C. Cycads have the largest sperm in the Plant Kingdom
D. Cycads are very ancient and grow very slowly
V. Division Gnetophyta
A. One example of these plants, Welwitschia, is found
only in the deserts of Namibia. It gets its very limited
supply of water from warm air currents and fog.
B. The gnetophytes are very bizarre and very distinctive.
VI. Economic Importance
A. Taxol is a cancer curative that comes from the Pacific Yew.
B. Before the 1860’s newspapers were made from rags.
C. Americans could save 1 million trees a year if toilet paper
were cut narrower.
D. The kauri pines of New Zealand produce amber (also
called Dammar), the only jewel produced by plants.
E. Turpentine comes from pines and is a major paint and
varnish solvent
F. Turpentine also produces extracts for lemon pudding.
G. Americans use 200,000 tons of paper each day.
H. John Muir helped found the Sierra Club to save the great
forests of the west.
Ancient ant or wasp
trapped in amber
Raw amber to be
used for polishing
into jewelry
Goodbye!
That’s all Folks!
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