Download Gymnosperms- Chapter 18

Gymnosperms- Chapter 18
Naked versus Enclosed Seed Plants
• Gymnosperms
– Gymno- gr. naked.
– Sperma- gr. seed.
• Angiosperms
– Angeion- gr. vessel.
– Sperma- gr. seed.
Extant Gymnosperms
• Match the common name on the right to the
phylum on the left.
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1) Cycadophyta
2) Ginkgophyta
3) Coniferophyta
4) Gnetophyta
a. ginkgo
b. conifers
c. cycads
d. gnetophytes
Cycadophyta
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Cycas- gr. palm.
Tracheids, but no vessel elements.
Sperm present, multiflagellated.
Palmlike leaves.
Pollen tube does not fuse with
the egg cell.
• Ovulate (megasporangiate) &
microsporangiate cones simple
& on separate plants.
• 11 genera & 140 species.
• Examples- Cycas & Zamia.
Zamia
Cycas
Ginkgophyta
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Yin- ch. silver, hing- ch. apricot.
Tracheids, but no vessel elements.
Sperm present, multiflagellated.
Fan-shaped leaves.
Pollen tube does not fuse with the
egg cell.
• Ovulate & microsporangiate cones
on separate plants; fleshy-coated
seeds.
• 1 genus & 1 species.
• Examples- Gingko biloba=
maidenhair tree.
Coniferophyta
• Con- gr. cone, fer- L. bear.
• Tracheids, but no vessel
elements.
• Sperm not motile.
• Needlelike or scalelike leaves.
• Pollen tube fuses with egg cell.
• Ovulate & microsporangiate
cones on same plant; ovulate
cones compound.
• 70 genera & 630 species.
• Examples- Pinus, Picea,
Juniperus, Abies, Cupressus.
True or False. These winglike structures are
female pollen grains.-------------------------->
Pinus- pine (Pinaceae).
Metasequoia- Dawn redwood.
Wollemia nobilis- Wollemi pine.
Gnetophyta
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Gneto- Malay gnenom.
Tracheids and vessel elements.
Sperm not motile.
Scalelike, leaflike, broad and
leathery leaves.
Pollen tube fuses with egg cell.
Ovulate & microsporangiate
cones compound & mostly borne
on separate plants.
3 genera & 70 species.
Examples- Gnetum, Ephedra,
Welwitschia.
Gnetum
Ephedra
Welwitschia